Japan is a country most affected by earthquakes. Earthquakes cannot be predicted and lead to large scale damage especially disruption of power supply. The high speed trains called Shinkansen are dependent in overhead cables for power supply and can get stranded in case of power failure caused by an earthquake. The trains may get stuck in tunnels or on bridges and may need to be moved to effect rescue. one way is to send a rescue diesel locomotive to move the train, however, this is a time consuming process. The Japanese are acutely aware of this fact.
A new series of trains called the N700S comprising 16 coaches will replace the present N700A series trains running on the Tokaido Shinkansen. This was the first dedicated high speed rail line in the world which had enamoured people with the first 0 series bullet trains way back in 1964.
There have been several modifications to the N700A to save space as well as weight. As result, the N700S trainset is much lighter than the N700A and it has give an opportunity for the Japanese Railways to install Li-Ion batteries in 8 out of the 16 coaches. These batteries will allow the trains and integral capability to be moved to safety in case of an emergency if the external power supply fails.