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Investigation of Serious Accidents and their Causes  |
When a serious accident occurs in the JR East area, we investigate the accident and its causes in order to proceed with R&D for future safety measures.
In tests recreating the situation at a recent derailment accident in the yard at Oku Station to find the cause of that accident, we found a phenomenon where wheels that had just been turned on a lathe effected derailment. |
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Investigation of series E531 EMU derailment accident at Oku Station
[Tests recreating situation at accident to find cause] |
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| Train run repeatedly in same way as on day of accident |
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Wheel surface that had just been turned on a lathe |
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| By running in same conditions as on day of accident, we found that the friction coefficient between wheel surfaces and rails increased on cars with wheels that had just been turned on a lathe running repeatedly in the sharply curved section of a turnout. That way, we were able to confirm predictive signs of flange climb derailment. |
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[Tests to confirm effects of countermeasures] |
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| We verified in the Kawagoe Rolling Stock Center and yard of Takahagi Station the effects of a method of turning wheels with a lathe and of flange lubrication. In that, we confirmed that there is no difference between methods of turning wheels and that the effect of lubrication is large. |
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