Japan: Recycled Cargo Ships Turned into Data Centers for AI

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Key Takeaways

1Japan is transforming cargo ships into data centers to address the shortage of land and freshwater.

2Mitsui OSK Lines and Hitachi are collaborating to convert ships into floating computing centers.

3The project aims to start in 2027, with facilities planned in Japan, Malaysia, and the United States.

💡Why it matters — This initiative could revolutionize digital infrastructure by leveraging underutilized maritime resources.

An Innovative Initiative for Digital Infrastructure

In the face of increasing constraints regarding land and freshwater resources, Japan is innovating by transforming cargo ships into floating data centers. This initiative is led by Mitsui OSK Lines (MOL), a major player in maritime transport, in partnership with Hitachi. Together, they aim to convert used ships into computing centers tailored to the growing needs of artificial intelligence. The project, which could come to fruition as early as 2027, will start in Japan before expanding to Malaysia and the United States.

Reinvented Car Carriers

Initially, MOL planned to repurpose a 120-meter ship weighing 9,731 tons. However, the project has scaled up and is now focusing on car carriers, ships designed to transport cars, offering around 54,000 square meters of usable space. This area rivals that of the largest terrestrial data centers in Japan. In terms of timelines, converting a ship into a data center takes only a year, compared to at least three for a land-based construction. MOL plans to leverage existing equipment on board, such as air conditioning systems and generators, while using seawater for cooling, thus reducing dependence on freshwater.

A Strategic Collaboration Between Giants

In this ambitious project, Hitachi plays a crucial role thanks to its expertise in data center management in Japan, Malaysia, and the United States. Responsibilities are clearly defined: MOL is in charge of ship conversion, port negotiations, and maritime maintenance, while Hitachi handles IT infrastructure, networking, and security.

A Favorable Economic Context

The Japanese economic context makes this project particularly relevant. In Tokyo, electrical connections for a data center can take between five and ten years. Additionally, land prices have skyrocketed in metropolitan areas, with some plots with electrical connections selling for up to 770% above official prices. The concentration of data centers around Tokyo and Osaka, combined with the growing demand linked to generative AI, exacerbates saturation. Japan, accustomed to turning its constraints into advantages, applies the same logic here: using ships to address the shortage of land and freshwater.

Precedents and Challenges to Overcome

This is not the first time MOL has explored this avenue. In July 2025, the company had already collaborated with Kinetics, an initiative by Karpowership, to test this concept. The current partnership with Hitachi marks a significant advancement. Microsoft had also experimented with an underwater data center in Scotland with its Natick project, which proved reliable but was not developed on a large scale. However, challenges remain, including salt corrosion that requires robust filtration systems, and the complex power supply for ships at dock. Japan is counting on its engineering expertise to overcome these obstacles and make this project a success.