If you have read my previous article about the route of the Japanese Chuo Shinkansen, you will know that I am both interested in and sceptical of the high speed Maglev train route now under construction between Tokyo and Nagoya, later to be extended until Osaka.
I recently came across an insightful article by German train expert Sven Andersen in which he highlighted some serious drawbacks of the superconducting magnetic levitation technology to be used for the project. As he pointed out, despite its exorbitant cost the new line will only add about 25% of the capacity of the existing Nozomi trains and 19% of the capacity of the Kodama and Hikari trains (the former only stop at major stations while the latter also stop at intermediate stations).
The mix of different train classes on either rail and wheel based or maglev routes means that (without two separate tracks in either direction) faster trains will have to pass slower trains while those are stopped at stations, with a need for switches to direct them to alternative track sections around each station. A new type of switch had to be developed for maglev trains which did not even exist yet when JR Central already decided on maglev as the technology for the new line: A lengthy piece of concrete track with embedded magnets is push sideways using hydraulic pistons, which takes considerable time. This slow operation of switches limits how closely different classes of trains can follow each other or how closely spaced they can arrive at different platforms at a head station (Tokyo Shinagawa and Nagoya or Osaka).
The two main reasons given for building the new Chuo Shinkansen line were 1) to provide more passenger capacity as the Tokaido Shinkansen line is running at capacity and 2) to provide an alternative route in case the Tokaido Shinkansen is hit by a natural disaster.
If the new maglev line can only provide a quarter or a fifth of the capacity of the existing line then it will not really be able to live up to either objective.
Andersen therefore strongly favours rethinking the plans by going for a rail and wheel-based approach on the new line. Though it would limit top speeds to 350 km/h instead of 500 km/h, it would allow many more trains to be run per hour, which dramatically increase capacity. It would also make it possible for trains operating on the new line to interconnect with the existing rail network, e.g. on to Hiroshima, Kyoto and other parts of Japan, instead of passengers having to get off one train with their luggage, ride 10 floors of escalators and then board a different train to get to their ultimate destination.
Like the German Transrapid Maglev system that was a commercial flop, the Chuo Shinkansen without wheels and rails will be an island within the rail network of an island – an amazing technical feat, but not really a solution for the needs of passengers in Japan and elsewhere.