It is not our practice to comment on the details of UK warhead design. I am withholding the information requested because it relates to national security and defence in the UK.
Each new release of Trident fire control software is certified by the US Government under the terms of the Polaris Sales Agreement (as amended for Trident). Under the agreement, the UK has the capability to validate the software models for software performance and verify that the findings are correct. This is undertaken and independently verified by UK experts to ensure the software meets our requirements before being issued to Royal Navy submarines.
The Royal Navy Trident Fleet consists of four Vanguard-class Ballistic Missile Submarines (SSBNs).
The full complement of a Vanguard-class submarine in a sea-going role is 160 men, consisting of 19 officers and 141 ratings. Of these, 140 go to sea.
Six crews are provided to man the four boats; a total requirement of 114 officers and 846 ratings. The current trained strength is 110 officers and 840 ratings.
Current policy is to ensure that any submarine is 100 per cent. manned at sea, with priority given to the SSBN force.
The Trident fleet consists of four Vanguard-class Ballistic Missile Submarines (SSBNs). Training requirements of the Trident fleet crew are subject to continual review and assessment. This process ensures that training remains up to date, and provides highly capable and well trained personnel onboard Trident submarines.