Yu Hibino

New train regulation method based on wind direction and velocity of natural wind against strong winds

Abstract Since there have been some railway accidents caused by strong winds in recent years in Japan, it is necessary to establish effective measures to prevent wind-induced accidents and ensure safety of train operation under strong winds. On February 22, 1994, a derailment accident was caused by strong winds on the Nemuro line of Hokkaido Railway Company. Railway Technical Research Institute carried out researches on investigation of the accident and measures at this section. As countermeasures, wind barriers were installed and a new train regulation method based on not only a natural wind velocity but also a natural wind direction was applied to the section. As a result, the railway company has had much less chances of slowdown and suspending of train operation than before and never experienced cancellation of train operation.

A Study on Vehicle Response to a Sudden Gust of Wind

In order to analyze the behavior of a railway vehicle that is subjected to a sudden gust of wind, we have conducted wind tunnel tests and running tests using a 1/10th scale train model. The feature of this model is that its spring stiffness is chosen considering the law of similarity between external forces and the resultant displacement of the car body. Using this model, we have examined aerodynamic forces acting on the surface of the car body and the behavior of the model in detail. Moreover, using the full-vehicle simulation program that we have developed in order to analyze the behavior of railway vehicles under crosswinds, we have examined the effects of the rapid changes of wind forces on overturning or wheel unloading ratios. As a result, it has been revealed that a sudden increase in wind force of less than 3 seconds can affect vehicle dynamic response considerably. On the other hand, a conventional static analysis is sufficient to evaluate a vehicle response for a slow increase in wind force of more than 3 seconds.