Britain retired its nuclear-powered 4,900t SSN Swiftsure Class fast attack boats in 2010, and has begun phasing out its follow-on 5,300t SSN Trafalgar Class, before the effects of the ocean’s constant squeezing and release start making them dangerous to use. The last Trafalgar Class boat is expected to retire by 2022, and replacements were required. Submarines are considered to be a strategic industry in Britain, which remains committed to nuclear-powered submarines for their entire fleet. As such, there was never any question of whether they’d design their own. The new SSN Astute Class were designed to be stealthier than the Trafalgars, despite having 39% more displacement at 7,400t submerged.
Britain’s 6 Swiftsure and 7 Trafalgar Class boats will eventually find themselves replaced by 7 of the new Astute Class. The new submarine class has had its share of delays and difficulties, but the program continues to move forward with GBP 2.75 billion in contracts over the past week.