Colt Data Centre Services and Indian real estate firm RMZ have started construction of a 64MW data center in Mumbai, the third facility at their Navi Mumbai campus, following the signing of a hyperscale customer.

The companies announced the start of work this week. Mumbai 3 will join buildings 1 and 2 at the campus, taking the site to 86MW of combined capacity. At full build-out, the Navi Mumbai campus could reach 148MW.

What will Mumbai 3's cooling setup look like?

Mumbai 3 will support a hybrid cooling architecture that combines traditional air cooling with direct liquid-to-chip cooling. The facility will also use a closed-loop system to reduce water consumption.

The design positions the building for high-density AI-era compute loads, where liquid-to-chip cooling has become standard practice among hyperscale operators.

In plain terms: the new building pairs two cooling methods and cuts water use at the same time.

How large is the Colt-RMZ joint venture?

Colt and RMZ announced their $1.7 billion joint venture in 2024. Under the JV, both companies committed to developing 250MW of data center capacity across Mumbai and Chennai. The pair are reportedly also targeting a project in Vizag.

Mumbai 3 is the latest step in that expansion. Colt DCS first announced its India entry in March 2023 with a planned ten-building campus in Navi Mumbai, followed by a site in Chennai.

RMZ, for its part, first announced plans to enter the data center space in 2023, with potential developments across Bengaluru, Chennai, Hyderabad, Mumbai, Pune, and the National Capital Region in Delhi.

The takeaway: the JV has 250MW committed across two cities, and Vizag may be next.

Where does this leave Colt's global portfolio?

Colt DCS operates 15 data centers today, with an additional 12 sites under development across nine cities in the UK, Europe, and the APAC region. The company says it has nearly 800MW of capacity under development.

The company's corporate history stretches back further than its data center business. Founded in 1992 and originally known as City Of London Telecom, Colt was acquired by Fidelity Investments in August 2015.

By the numbers, Colt DCS now counts one completed campus build-out phase after another across three regions, with India as its fastest-scaling market by announced capacity.