Photostories
Defending Railways Against Nature

The geography and climate of Japan do not favour construction and operation of railways. The ground is soft and there are frequent, severe earthquakes. The Pacific coast is lashed by strong winds and heavy rain during the summer typhoon season and the Sea-of-Japan coast suffers from heavy snowfalls. Many lines must pass through mountainous areas, requiring embankments, slopes, bridges and tunnels, all of which are vulnerable to these natural hazards. Railway engineers spend a great deal of effort defending structures and tracks against nature. Some examples are shown below and on pp.66–67.
Makoto Shimamura

Landslide and Rockfall Prevention
Photo: This Narita Express train is emerging from a tunnel portal heavily armoured against landslides by a concrete grid.
(JR East)
Photo: Sobu Line embankments are well protected against erosion.
(JR East)
Photos: Embankment slip detectors and line monitoring systems on the JR Sobu Line help ensure that Narita Express (NEX) trains maintain their tight schedule to the airport.
(JR East)
Photo: Link net fences are being introduced in Japan to protect tracks from falling rocks.
(RTRI)
Photo: Rockfall shelters and fences protect JR East's Banetsu West Line from the towering overhead mountain face.
(JR East)
Photos: This experiment simulates embankment failure under heavy rainfall conditions. The picture on the right shows the extent of embankment erosion after a heavy artificial rainfall.
(RTRI)

Wind
Photos: The Shiraitogawa Bridge on the Tokaido Main Line was a popular spot for railway enthusiasts but suffered from heavy cross winds (left—M. Mashima Photo Office), before it was protected by wind-breaks (centre and right—JR East) which detract from its visual appeal.
Photos: The effects of cross winds on the Series E1 shinkansen crossing a viaduct (left) and the Series 415 EMU (right) on an embankment were simulated using scale wind tunnel experiments.
(RTRI)

Snow
Photo: In snow-bound areas, avalanche detectors like this structure stop train operations by issuing a warning signal.
(JR East)
Photo: Trackside laser beams are used to measure snow depths.
(JR East)
Photo: Uenoshiri on JR East's Banetsu West Line is protected against avalanches by snow barriers on the slopes overlooking the line.
(JR East)
Photo: A rotary snowplough clears deep snow from the Yonesaka Line in northern Honshu.
(JR East)
Photo: Trackside water sprinklers on the Joetsu Shinkansen help melt snow on the track.
(JR East)

JR East's online monitoring and alarm system collects data on weather and track conditions from wayside measurement devices and transmits it to a control centre. The system identifies natural hazards based on real-time data and issues service restriction and resumption commands.

Photo: Mud and rock slides are a serious threat and various devices are used to detect them.
(JR East)
Photo: JR East's monitoring and alarm terminals display information that identifies natural hazards, and issue service restriction commands.
(JR East)
Photo: Trackside anemometers measure cross winds.
(JR East)
Photo: Seismometers at 40-km intervals (20 km in Greater Tokyo) stop train operations in the event of a serious earthquake.
(JR East)
Photos: Rain, water-level, and wave gauges (left to right) monitor track flooding hazards.
(JR East)