Vanguard could serve longer

Already the RN's Vanguard fleet of SSBNs have had their service lives extended from 25 years to 30 because of delays in designing and building a replacement now that could be extended further if there are more delays. The NAO says the current timetable is already challenging and if Astute-style delays occur then the Vanguard boats may have to stick around until later in the 2020s. Currently the fleet is due to start being withdrawn around 2023. The MOD are not counting on it but are looking to see what the implications might be. So it'll probably happen then.