The UK Royal Navy (RN) has completed a second successful trial in its development of the capability to launch and recover uncrewed systems from submarine torpedo tubes.
An Astute-class nuclear-powered attack submarine (SSN) conducted the torpedo-tube launch and recovery (TTL&R) of an uncrewed underwater vehicle (UUV) during recent testing in the Mediterranean, the navy said in a statement on 22 July.
“The torpedo tube-launched vehicles will increase the capability options for UK SSNs, and support underwater reconnaissance, underwater communications, and seabed warfare missions,” it added.
An RN spokesperson confirmed to Naval News that the trial was the second in-water activity to take place. The first occurred in November 2024, again with an Astute boat used.
The spokesperson added:
“Development of [the RN’s] Project Scylla has been an ongoing endeavour encompassing both at-sea and shore-side trial elements,”
Project Scylla is a national programme to develop a TTL&R capability, occurring within the context of the AUKUS Undersea Robotics Autonomous Systems (AURAS) project, which itself is part of Pillar 2 of the Australia/UK/US (AUKUS) strategic partnership. Under AUKUS, Pillar 2 is focused on developing and integrating various advanced technologies; Pillar 1 is delivering an SSN – the SSN-AUKUS boat – for Australia and the UK.
“We’ll be continuing to collaborate on this capability under AUKUS Pillar 2 and within the context of the UK’s 2025 Strategic Defence Review (SDR) to accelerate delivery to the frontline,” the RN spokesperson explained.
The latest TTL&R trial was conducted by the UK Submarine Delivery Agency’s Autonomy Unit, working together with L3Harris and using one of the company’s Iver4 UUVs. The trial demonstrated the pace at which new capabilities can be developed within an international partnership construct, the navy said in its statement.
“Delivery of these trials demonstrates our commitment to the use of advanced capabilities as part of a future ‘hybrid fleet’, and are a big step forward in delivering new capability to the submarine service,” Commodore Marcus Rose, the RN’s Deputy Director for Underwater Battlespace Capabilities, added in the statement.
The SDR, published in June, announced the ambition for the RN to transition to a ‘hybrid navy’, including rapidly evolving how it fights for example by blending a mix of crewed and uncrewed platforms. The review highlighted the importance of both SSNs and UUVs as central elements of this planned transition.
SDR also provided details of the navy’s new ‘Atlantic Bastion’ concept. To counter the growing underwater threat in the North Atlantic through enhancing anti-submarine warfare (ASW) outputs by integrating capabilities like UUVs onboard SSNs within a layered, multidomain ASW approach, ‘Atlantic Bastion’ is designed to augment North Atlantic deterrence and defence including in support of NATO requirements. This North Atlantic commitment is a primary role SDR set out for the UK’s armed forces.
The RN statement added that delivering advanced capabilities including uncrewed, autonomous systems to the frontline is a central element of the navy’s ‘Atlantic Bastion’ ambition, and increases overall fleet warfighting capabilities.
The US Navy (USN) has a TTL&R UUV deployed operationally at sea onboard the Virginia-class SSN USS Delaware, in the form of an HII Yellow Moray (REMUS 600) UUV, having completed testing and trials of this system onboard the boat. Previously, the USN has also tested TTL&R capability from a 688/Los Angeles-class SSN, using an L3Harris Iver UUV. The USN’s operational intent is to have the capability permanently available at sea.
Naval News comments
Integrating SSNs and UUVs is a core component of building a layered network of sensors for ‘Atlantic Bastion’. It also illustrates how the operational benefits of both platforms can be optimised to counter the Russian submarine threat in the North Atlantic.
An established naval adage is that the best way to fight a submarine is with another submarine. The RN’s Astute-class SSNs, together with the USN’s Virginia-class and remaining Los Angeles-class boats, offer a collection of highly capable ASW platforms to counter the North Atlantic ASW threat at both national and NATO levels. Although numbers of such platforms remain relatively limited – especially in the context of an underwater battlespace that reaches right across the North Atlantic, from its western waters to the Barents Sea and Arctic Ocean – harnessing TTL&R UUV capability can help add sensing mass across this distance. For example, the submarine can deploy the UUV to undertake what are termed ‘3-D’ (‘dull, dirty, and dangerous’) tasks like providing sensing presence at choke points or conducting surveillance of seabed critical infrastructure, leaving the SSN to roam more widely, to seek, detect, and track any submerged, moving targets the UUV or the submarine itself may pick up.
The first phase of ‘Atlantic Bastion’, named ‘Atlantic Net’, is focused on enhancing this sensing mass through deploying UUVs in numbers for autonomous operations in the North Atlantic. With the RN continuing with its TTL&R capability development, this raises the possibility of whether it could be integrated into AUKUS Pillar 1, which is after all delivering an SSN.
