UK Nuclear Challenges: Keeping ‘CASD’ Afloat (excerpt)
(Source: International Institute for Strategic Studies; issued May 22, 2020)
Two of the Royal Navy’s ballistic missile submarines, including HMS Vigilant shown here undergoing maintenance at Faslane, have not been at sea for over a year, while HMS Vanguard has been in maintenance since December 2015. (Royal Navy photo)
Can the United Kingdom sustain its Continuous At-Sea Deterrence? After 50 years of unbroken CASD, reports of technical problems with the Royal Navy’s fleet of nuclear-powered ballistic-missile submarines, as well as COVID-19-related challenges, have added to concern that this continuous at-sea presence is at risk.

The United Kingdom marked 50 years of unbroken Continuous At-Sea Deterrence (CASD) with the Royal Navy’s nuclear-powered ballistic-missile submarines (SSBNs) in 2019, but reports that half its fleet was laid up for over a year recently with technical problems have added to concern that this continuity is at risk.

The Vanguard-class SSBNs will now have to operate into the 2030s, well beyond their original planned lifespans, even if the successor Dreadnought class is delivered on time. In addition, the COVID-19 pandemic is causing further complications.

The chair of the House of Commons Defence Select Committee, Tobias Ellwood, drew attention to the potential strains on the CASD mission at a committee hearing on 17 March, when he suggested that two of the four Vanguard class had been “out of the water for more than a year.”

CASD requires at least one boat always to be on patrol (usually for up to three months at a time). Typically, a second and third boat are either training to take over the next patrol or have just returned and are in maintenance at the boats’ home base at Faslane in Scotland. The fourth, meanwhile, would likely be undergoing a more extended Long Overhaul Period (LOP) at Devonport naval base.

Problems arise if there are significant delays in the maintenance and LOP work. That, it seems, has been the recent situation, with CASD relying on just two boats to conduct overlapping rotational patrols.

One of the submarines concerned is HMS Vanguard, in a scheduled LOP since December 2015. Originally planned to last three and a half years, the extensive refit has overrun by about a year so far and Vanguard is unlikely to rejoin the fleet this year as previously intended. The identity of the second vessel, which apparently required extended maintenance at Faslane, is unconfirmed. (end of excerpt)

Click here for the full story, on the IISS website.


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