A consortium of four Tokyu Group companies announced on March 23 that it will install a modular data center beneath an elevated section of the Oimachi Line in Tokyo starting in June 2026, according to a press release published by PR Times. The trial aims to determine whether compact server infrastructure can operate reliably in the space under active railway overpasses, with all the environmental aspects that come with them, such as vibration and differing thermal conditions.
Tokyu Corporation, Tokyu Electric Railway, It's Communications Corporation, and Tokyu Construction are all participating. Tokyu Construction is developing the modular unit itself, Tokyu Electric Railway is providing the site beneath the elevated track, and It's Communications will supply fiber connectivity using optical cable already installed along the railway.
The modular unit packages servers, cooling, and power supply equipment into a container-sized enclosure that can be deployed without constructing a full building. The consortium plans to measure the server housing's sound insulation, thermal insulation, vibration isolation, and cooling performance under the specific environmental conditions of a railway overpass. Based on the results, it will assess whether the format is viable for deployment in other locations along the Tokyu network.
Optical fiber network is already established along the rail lines
One advantage the consortium is banking on is the large-capacity optical fiber network that It's Communications has already built along Tokyu's rail lines. Rather than trenching new fiber to connect a facility, these under-track installations could tap directly into existing backbone infrastructure. The consortium also said it’s considering future data center deployments across the broader Tokyu Line network, including in Shibuya, as part of a longer-term digital infrastructure strategy.
The experiment takes place against a backdrop of severe infrastructure challenges in Tokyo's data center market. Yasuo Suzuki, executive vice president and managing director for Japan and APAC at NTT Global Data Centers, told Data Center Knowledge in September 2025 that power grid connection wait times in inner Tokyo can stretch five to 10 years.
Tokyo land prices rose 69% in 2024, according to Mordor Intelligence, and the city already has 132 operational data centers with at least 18 more under construction. Medium-sized facilities in Japan are growing at a 12% compound annual growth rate through 2031, according to the same research firm, outpacing larger builds because they can be deployed faster in constrained urban environments.
Luke James is a freelance writer and journalist. Although his background is in legal, he has a personal interest in all things tech, especially hardware and microelectronics, and anything regulatory.
The data centres are intended for generative AI, according to the press release.
This is sad ... Tokyu has some trains/stations that I had planned to use on a upcoming trip to Tokyo.
Now, I'd have to take long detours on my feet/bike/taxi to boycott them.
At least, I wouldn't have to do it every day....
Would joining onto these existing fiber runs impact other users, a bit like when more people using cable modems in a neighborhood meant progressively less performance per user? At least that's what I recall hearing about cable internet access .
