SUBMARINE DISMANTLING PROJECT
MOD · MOD_0135_2122-Q1
Department page: Ministry of Defence
| Data as at | Rating | End date | Whole-life cost |
|---|---|---|---|
| March 2024 | Amber (the department's own assessment) | 31 March 2027 | £362m (price basis not stated) |
| March 2025 | Amber (the department's own assessment) | 31 March 2027 | £400.38m (price basis not stated) |
| March 2026 | Red (the department's own assessment) | 31 October 2028 | £541.73m (in 2024/25 prices) |
Each year’s cost is shown with its price basis. Costs are not compared between years: the March 2024 and March 2025 reports state no price basis, and from March 2026 costs are in 2024/25 prices.
The department’s commentary
This is the department’s own commentary. It may use different prices from the table above, so its figures may not match.
March 2026
Rating: 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.
March 2025
Rating: Compared to financial year 23/24-Q4, the Delivery Confidence Assessment rating at 24/25-Q4 remained at AMBER. This is primarily due to the following factors. The project is continuing to progress in line with its maturing schedule. However, this is a novel and complex project which can encounter challenges that cannot necessarily be planned for.
Schedule: Compared to financial year 23/24-Q4, the project's end-date at 24/25-Q4 remained at 31/03/2027.
Cost: Compared to financial year 23/24-Q4, the project's departmentally agreed Whole Life Cost at 24/25-Q4 (measured in £m) increased from 362 to 400. This is primarily due to the following factors. The maturation of infrastructure costs.
Source: NISTA Annual Report 2024-25 (data)
March 2024
Rating: Compared to financial year 22/23-Q4, the Senior Responsible Owner's Delivery Confidence Assessment rating at 23/24-Q4 remained at Amber. This is primarily due to the following factors. The project is continuing to progress in line with its maturing schedule, however, this is a novel and complex project and learning by doing encounters difficulty and challenge that cannot necessarily be planned for.
Schedule: Compared to financial year 22/23-Q4, the project's end-date at 23/24-Q4 is scheduled to finish on 2027-03-31. The date is based on a 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 22/23-Q4, the project's departmental-agree Whole Life Cost at 23/24-Q4 increased from 298m. to 362m. This is primarily due to the following factors. An increase in the number of employees required to complete the work and the impact of inflation e.g. the rising cost of materials.
Source: IPA Annual Report 2023-24 (data)
Names, figures, dates, ratings and commentary are as the department reported them. Where a rating, cost or date is withheld, the file’s wording is shown. Every major project →