UK's newest Astute-class submarine sets sail

The UK’s newest Astute-class submarine, HMS Agamemnon, has left BAE Systems’ shipyard in Barrow-in-Furness and headed out to open sea for the first time.

The 7,400-tonne, 97-meter-long submarine left the shipyard on September 25 and traveled through the yard’s dock system into the Walney Channel and then the Irish Sea. It is the first time Agamemnon has gone to sea.

Agamemnon will now undergo a series of sea trials and tests before joining the other five Astute-class submarines already in Royal Navy service at His Majesty’s Naval Base Clyde.

The submarine was formally commissioned into the Royal Navy in September 2025 in a ceremony attended by King Charles III. Before leaving Barrow, it completed its first underwater dive in October 2025 as part of a trim and basin dive designed to test the submarine’s stability, watertight integrity and onboard systems.

Agamemnon is the sixth of seven Astute-class submarines being built by BAE Systems at Barrow-in-Furness. The submarine was launched in October 2024 and is named after the ancient Greek king Agamemnon.

The Astute-class is designed for a range of missions, including covert surveillance, intelligence gathering, anti-submarine warfare and precision strike. The submarines are equipped with Spearfish heavyweight torpedoes and Tomahawk Block IV land-attack missiles.

"The Astute class submarines are equipped with the latest technologies to silently circumnavigate the globe without surfacing, whilst fulfilling a range of tactical roles for the Royal Navy," Steve Timms, Managing Director of BAE Systems’ Submarines business, said.

"The departure of HMS Agamemnon, the sixth of seven such submarines that we are building here in Barrow, demonstrates the growing momentum underpinning our submarines business and is a proud moment for everyone involved across the UK’s submarine enterprise."

"In an increasingly dangerous world, sea power remains fundamental to keeping our country and people safe. Our submarine fleet is essential to that effort, which is why I am delighted that HMS Agamemnon, the sixth of our Astute-class submarines, has now begun sea trials and will soon arrive at HMNB Clyde to join the fleet," Royal Navy First Sea Lord General Sir Gwyn Jenkins commented.

With BAE Systems having delivered the first six Astute-class submarines, progress on the final boat, Achilles, is at an advanced stage of construction. BAE Systems is also undertaking early design and concept work for the Royal Navy's next generation of submarines which will eventually replace the Astute class, referred to as SSN-AUKUS.