[JP] Japan’s Railways Turn to Superconducting Power Cables

[maglev]

Japan’s Railways Turn to Superconducting Power Cables

Japan’s railway companies are turning to superconducting technology to address two major challenges: power inefficiency and labor shortages in train operations. Superconductivity—well known for powering maglev trains with magnetic levitation—can also transmit electricity with zero resistance, eliminating transmission loss and voltage drops common in conventional systems.

JR East began a live trial this March on a 408-meter stretch of the Chuo Line near Tokyo using a superconducting power cable. Developed by the Railway Technical Research Institute, the cable is cooled with liquid nitrogen to –196°C and consists of metals like yttrium, allowing for efficient energy transfer. Unlike traditional DC lines, which require substations every 2–5 kilometers to compensate for voltage loss, superconducting cables could reduce or eliminate the need for such dense infrastructure. This is especially attractive amid a growing shortage of technical maintenance staff.

The first operational test occurred in 2024 on a 102-meter section of the Izuhakone Railway in Shizuoka, drawing interest from over 60 railway firms across Japan. Now, companies like Tokyo Metro are monitoring developments closely, as the technology could help consolidate urban substations, free up valuable land, and simplify upkeep.

Despite its promise, the technology faces hurdles. Maintaining superconductivity demands constant cooling, requiring its own energy supply. Material and operational costs must be reduced for broader adoption. However, according to Masaru Tomita, director at the Maglev Systems Technology Division, once cable installations reach at least 1 km in length, the system becomes more energy-efficient than traditional setups. Installation costs are estimated at less than half that of a standard substation.

Ultimately, Japan’s rail industry sees superconducting cables as a way to cut energy waste and reduce labor demands—potentially achieving both goals through a single innovation.

Info based on https://mainichi.jp/english/articles/20 ... sc/030000c Accessed 2025-05-18