UK Will Start SSN-AUKUS Submarine Build in 2027
The planned attack submarine fleet will replace the aging Astute-class vessels starting in the late 2030s.
Updated on Sept. 22, 2026 in Nuclear
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The United Kingdom has scheduled the initial steel cutting for its first SSN-AUKUS submarine for 2027. This development marks the formal start of a production program designed to eventually replace the Royal Navy's current fleet of five active Astute-class attack submarines.
Why it matters
The program aims to modernize naval capabilities to meet specific NATO and Indo-Pacific strategic requirements. It functions as a key component of a long-term defense strategy that will also oversee the construction of four new Dreadnought-class ballistic missile submarines.
The upcoming SSN-AUKUS boats will supersede the current Astute-class submarines, which measure 318 feet in length and displace 7,400 tonnes while submerged. The new program targets a production rate of one boat every 18 months, supported by new SMITE2 shore-testing infrastructure.
The players
BAE Systems
A global defense prime contractor that manages the Barrow-in-Furness shipyard and specializes in the design and construction of complex naval platforms.
Rolls-Royce Submarines
A division of the global engineering firm that designs and manufactures the nuclear reactor technology used to power Royal Navy submarines.
The details
The program utilizes a collaborative nuclear propulsion design provided by Rolls-Royce, which will be integrated into a hull architecture developed through technical cooperation between the UK and Australia. Construction in the UK is centered at the BAE Systems facility in Barrow-in-Furness, while Australia has designated Osborne as its construction site. The process integrates advanced shore-testing protocols to validate complex submarine systems before final assembly.
Timeline
2027: Steel cutting begins for the first SSN-AUKUS submarine.
Late 2030s: Expected entry into service for the first unit.
2030s-2070s: Anticipated strategic service life for the new submarine fleet.
The Tech Race
The SSN-AUKUS program succeeds the current Astute-class submarine fleet, marking a generational transition in naval propulsion technology. It positions the UK and Australia to meet long-term strategic requirements as they move toward the 2030s deployment window.
The program is structured to support 21,000 specialized jobs across the UK, primarily within the engineering and manufacturing sectors in regions like Barrow-in-Furness and Derby. These roles will focus on the long-term production and maintenance pipeline that extends through the 2070s.
The takeaway
The program marks a transition toward a sustained production cadence for nuclear-powered attack submarines through the coming decades. Watch for the 2027 steel-cutting milestone as a key indicator of whether the proposed 18-month production timeline remains feasible.
Further reading
For more information on the evolving standards for naval nuclear programs, see Nuclear.
Source note: This article includes information reported by 19FortyFive.
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