HMS Tireless went on to become the Royal Navy's longest-serving nuclear submarine.
The third submarine of the Trafalgar class weighed more than 5,000 tonnes and was 85 metres long.
The nuclear-powered vessel, launched in 1984, played a key role in helping search for Malaysian Airlines flight MH370 in April 2014, one of her last official duties before being decommissioned.
In October 1985, HMS Tireless left Ramsden Dock bound for five weeks of sea trials before she joined the second submarine squadron at Devonport.
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Tireless was the 15th fleet submarine, and the 14th to be built by VSEL, to enter service with the Royal Navy and her main role was to seek out and destroy enemy subs, and was known as one of the Cold War warriors.
Armed with Tigerfish wire-guided torpedoes and Sub-Harpoon anti-ship missiles, HMS Tireless had a pressure hull diameter of 9.83 metres and was also effective against surface ships.
In 2007 an explosion onboard killed two sailors during a joint British-American Arctic icecap exercise.
She took to international waters again in 2010 as part of a major anti-submarine warfare exercise in the Gulf of Oman with vessels from France, Australia and the US.
Directed by the UK Maritime Component Command based in Bahrain, the navy ships and subs conducted 'cat and mouse' chases with HMS Tireless adopting the role of 'mouse.'
She was decommissioned back in Devonport on June 19, 2014.
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