Press Releases（Archive）
Shinkansen Early Earthquake Detection System Improvements
Supplement 3
The Shinkansen Early Earthquake Detection System, which is designed to detect earthquake activity early and cause Shinkansen trains to stop, is undergoing improvements on the Tohoku, Joetsu and Nagano Shinkansen lines.
- Changes to Operating Rule Criteria (switchover completed by end of September 2005)
- For the earthquake index, JR has switched from gal units to SI units.
- Effective operating rules are used to predict railway structural damage accurately, without any loss of safety.
- These changes are expected to reduce the incidence of speed restrictions and operating suspensions by about 30%.
SI index: An index that can express the impact of an earthquake by taking into account the acceleration action time and a structure's unique cycle, factors that could not be captured using earlier methods.
Units: cm/sec (same as speed) = kine; acceleration: cm/sec2 = gal
- Changes in methods for estimating earthquake scale, etc. [Scheduled for completion at the end of FY2005]
- The system is changing from a method that estimates the size of subsequent secondary waves at each seismometer to a method of estimating the scale of the focus of the earthquake.
- This will shorten seaside seismometer estimation time from three seconds to two.
- Addition of a function for stopping power transmission over the range affected by an earthquake [Scheduled for completion at the end of FY2005]
- Function added to shut off power transmission throughout an area anticipated to sustain damage, based on the earthquake’s presumed focus and scale.
- Increased installation of wayside seismometers [Scheduled for completion at the end of FY2006]
- The 47 wayside sites that currently have seismometers will be increased by 28, and the distance between two seismometers will be less than 20km (13km on average).
In the most effective anticipated case, this will shorten detection time by one second.
Moreover, in addition to the wayside system improvements, JR is examining improvements for Shinkansen cars themselves, including changing over to emergency braking operations that do not have to go through an ATC (automatic train control) system when power transmission is stopped, and a method for shortening the time for brake control from two seconds to one.
Attachment
Shinkansen Early Earthquake Detection System Improvements [PDF/102KB]
