Question to the Ministry of Defence:

To ask Her Majesty’s Government, further to the Written Answer by Earl Howe on 19 January (HL4885), whether the dates given in fact show that the time from laying down to operational handover for HMS Astute was nine years and seven months, and that for HMS Artful it will be 11 years.

The build time of a submarine is measured between the start of manufacture and operational handover to the Royal Navy. Using this metric, the build time of HMS Astute was 170 months and for Artful was 137 months.

Keel laying and commissioning have no bearing on the build programme. These are ceremonial milestones only: commissioning can happen before or after operational handover. Using these milestones, however, the time taken from keel laying to commissioning was nine years and seven months for HMS Astute and 11 years for Artful.