Three of four UK Vanguard submarines reported at sea

Three of the Royal Navy’s four Vanguard-class ballistic missile submarines were reported at sea at the same time, an unusual concentration that officials have not explained. At least one was said to be conducting a routine continuous deterrent patrol, while the fourth, HMS Victorious, was at Devonport for maintenance. The Ministry of Defence declined to comment on the deployment. The identities and confirmed assignments of the three submarines at sea were not established in the reporting. An expert said one may have been preparing to relieve the patrol submarine, while another could have been undertaking sea trials or workup activity. Those explanations were not confirmed. The UK maintains at least one submarine on continuous at-sea deterrent patrol, a mission that a specialist account says has continued without interruption since 1969. Vanguard-class boats carry Trident II D5 ballistic missiles, but the UK no longer publicly discloses the number of missiles or warheads aboard individual submarines. The reported presence of three boats at sea does not establish that all three were conducting deterrent patrols. The specialist account said three Vanguard submarines were last...