USS Colorado named first U.S. submarine for AUKUS rotational force in Western Australia

By Calvin Strand

WASHINGTON — The Virginia-class attack submarine USS Colorado will be the first U.S. Navy boat assigned to Submarine Rotational Force-West, the planned rotation of American and British nuclear-powered submarines through Western Australia under the AUKUS pact, the three allies’ defense chiefs announced in a statement dated Oct. 27 in Australia.

In a joint statement released by the Department of War, Secretary of War Pete Hegseth, Australian Deputy Prime Minister and Defence Minister Richard Marles and British Defence Secretary Wes Streeting said the Colorado (SSN 788) is assigned to the force “beginning in late 2027.” They called the selection “a significant milestone for AUKUS Pillar I and … a decisive step in strengthening collective deterrence in the Pacific.”

“As President Trump has stated, and Prime Minister Albanese and Prime Minister Burnham have reaffirmed, AUKUS is moving ‘full steam ahead,'” the statement said.

The rotational force, known as SRF-West, is expected to host up to four U.S. fast-attack submarines and one British submarine at a time at HMAS Stirling, the Royal Australian Navy base near Perth. The three governments say it will speed Australia’s readiness to “own, operate, maintain, and regulate” its own conventionally armed, nuclear-powered submarines while expanding maintenance options for allied boats in the region. The statement said the force was established “at Australia’s invitation” and will operate in accordance with agreements including the U.S.-Australia Force Posture Agreement, consistent with the partners’ obligations under the Nuclear Non-Proliferation Treaty and Australia’s under the South Pacific Nuclear Free Zone Treaty.

A month of maintenance by Australian workers

The announcement coincided with the Colorado’s arrival at Stirling on Tuesday local time for a monthlong maintenance period, according to a Navy release distributed by DVIDS. It is the fourth submarine maintenance period in Western Australia under AUKUS and the first in which Australian civilians, more than 30 technicians from the government shipbuilder ASC Pty Ltd., will perform routine maintenance on a Virginia-class submarine in the state, working alongside specialists from Pearl Harbor Naval Shipyard.

The Navy said the Colorado is the sixth U.S. nuclear-powered attack submarine to visit Stirling since the allies announced their “Optimal Pathway” plan in 2023, and the third to undergo maintenance there in the past 12 months. It is assigned to Submarine Squadron 3 and, according to the Navy, will “help formally establish” SRF-West when it returns in late 2027.

“This maintenance period brings us closer to establishing SRF-West,” said Rear Adm. Doug Adams, the Navy’s director of AUKUS, international and systems. Rear Adm. Chris Cavanaugh, commander of the Pacific Fleet’s submarine force, said the effort is “driven by the challenging strategic environment in the Pacific and our collective desire to deter aggression and ensure peace through strength.”

Australian Rear Adm. David Mann of the Australian Submarine Agency said, according to the Navy release, the maintenance periods “have been critical to Australia being on track to start SRF-West in 2027.” Workers will use new Australian-built infrastructure, including a sail safety walkway known as the “racetrack” and upgrades to Stirling’s Diamantina Pier, according to the Navy.

Background

The Colorado was commissioned in 2018 and is a Block III Virginia-class boat, Naval News reported. Under the AUKUS plan, rotations at Stirling are a step toward Australia buying Virginia-class submarines from the United States and later building a new class of boats with Britain.

The Washington Inquisitor is seeking comment from the Department of War, the Navy, the Australian Embassy and the British Embassy on the timeline.