SUBMARINE DISMANTLING PROJECT

Military Capability

Record date: 31 March 2026

Whole-life cost: £541.7m
Published schedule: 29/03/2013 – 31/10/2028
NISTA delivery confidence: Not disclosed
Senior responsible owner: Lorraine Russell

What the project is for

The Submarine Dismantling Project covers the preparation and execution of the safe and secure dismantling of the first defueled, decommissioned, Royal Navy submarine, Swiftsure, in Rosyth, by the end of 2026.

Departmental delivery commentary

Compared to financial year 24/25-Q4, the NISTA/SRO Delivery Confidence Assessment rating at 25/26-Q4 decreased to Red. This is primarily due to the following factors. 1. The project’s novel and complex nature, which continues to present unforeseen challenges. 2. While progress is being made, ongoing prime supplier performance issues and third-party supply chain risks pose potential delays. 3. Additionally, gaps have been identified in the project’s planning, controls, and commercial arrangements, which are impacting overall delivery assurance.

Schedule

Compared to financial year 24/25-Q4, the project's end-date at 25/26-Q4 increased from 31/03/2027 to 31/10/2028. This is primarily due to the following factors; The date is based on a continually maturing schedule and its achievability. This date represents the formal closure of the project and is separate from the milestone to complete the dismantling of Swiftsure by 2026.

Cost

Compared to financial year 24/25-Q4, the project's departmentally agreed Whole Life Cost at 25/26-Q4 (measured in £m) increased from £400.382 to £489.563. This is primarily due to the maturation of infrastructure and other costs.

Benefits

Compared to financial year 2024/25-Q4, the project's departmental-agreed monetised benefits at 2025/26-Q4 remained at £0m.