# HMS Agamemnon submarine sea trials

> Live situation record from CLSTR: https://clstr.news/situations/hms-agamemnon-submarine-sea-trials
> Updated: 2026-09-25T15:34:51.000Z. Sources: 6. Developments: 2.

The HMS Agamemnon, a £1.65 billion Astute Class nuclear-powered attack submarine, has departed the BAE Systems shipyard in Barrow-in-Furness to begin sea trials. The 97-metre vessel is the sixth of seven Astute Class submarines constructed by BAE Systems.

The construction process spanned 13 years since the vessel was originally commissioned in 2013. After departing the shipyard and traversing the Walney Channel, the submarine entered the Irish Sea. Upon the conclusion of these trials, the vessel is expected to join the Royal Navy’s existing Astute Class fleet to support UK security and NATO collective defence.

## Timeline

### 2026-09-25: HMS Agamemnon begins sea trials after 13 years of construction

The UK's HMS Agamemnon, a £1.65 billion Astute Class nuclear attack submarine, has begun sea trials after 13 years of construction at BAE Systems.

4 sources. https://clstr.news/cluster/hms-agamemnon-begins-sea-trials-after-13-years-of-construction

### 2026-09-12: United Kingdom: HMS Agamemnon sea trials and Prince Harry's public return

The UK's HMS Agamemnon nuclear submarine enters final sea trials, while Prince Harry begins a series of public engagements in Britain, including the Invictus Spirit Awards.

2 sources. https://clstr.news/cluster/united-kingdom-hms-agamemnon-sea-trials-and-prince-harrys-public-return

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Cite as: HMS Agamemnon submarine sea trials. CLSTR, https://clstr.news/situations/hms-agamemnon-submarine-sea-trials