Herne aims to be affordable, autonomous naval combat mass

The demands on modern navies are growing. Technological advancements, constrained budgets, and the increasing complexity of operational requirements mean forces must find innovative ways to do more with less.

The Herne platform, an Extra-Large Autonomous Underwater Vehicle (XLAUV) developed by BAE Systems in collaboration with Canadian firm Cellula Robotics, aims to address this need.

The craft itself is a 12-metre-long, 8–10-tonne platform constructed around a lightweight aluminium frame, designed for flexibility and endurance. It features two modular payload bays, each offering a 2,500-litre capacity, which can be reconfigured into a single 5,000-litre bay to accommodate larger equipment such as torpedoes, towed arrays, or other payloads. The payload areas are free-flooding, requiring components to be housed in smaller sealed pressure cans,  rather than one large pressure hull, a design choice that enables rapid reconfiguration for diverse mission profiles.

Its propulsion system includes two electric motors driving independent propellers, achieving a sprint speed of 8 knots and a cruising speed of 3 knots. With a depth rating of 3,000 metres, Herne is capable of operating in environments beyond the reach of most crewed submarines.

Power is supplied by lithium-ion batteries, enabling missions of 7–10 days, and in the future, it is hoped that hydrogen fuel cells could be used for extended endurance of up to 45 days or 5,000 kilometres. Neutral buoyancy is maintained using filled foam cells and ballast systems, ensuring stability and compensating for payload deployment underwater.

The vessel also features lateral and vertical thrusters for enhanced manoeuvrability, making it adept at navigating complex undersea environments. Herne is designed for ease of deployment, fitting into a standard 40-foot container and deployable via ships, submarines, or even air transport. Its modular construction and advanced autonomy allow it to be a versatile and efficient addition to a range of naval operations.

Recently showcased in a two-week demonstration on the south coast of England, Herne offered insights into how autonomous systems can augment naval capabilities.

During a media visit to the south coast to see Herne in action, it was clear how much passion and effort the team had put into this project. The visit wasn’t just about watching the platform surface and move around; it was about understanding the collaborative work and forward-thinking ideas shaping its development. You can watch our footage of the event below. The underwater shots come from BAE, and we don’t own a submarine with a camera.

During the visit, I was able to speak to a number of people about the project.

Nick Martin, the Project Manager for the Extra-Large Autonomous Underwater Vehicle project, spoke about the tight timelines and close partnerships that have helped turn Herne into a reality in just over a year. He described how the platform’s flexible design lets it adapt to a range of missions, from surveillance to deploying advanced effectors.

Tim O’Neill, Business Development Manager at BAE Systems Maritime Services, shared how the team is focused on creating something that navies can use in the real world. He talked about Herne’s balance of affordability and capability, explaining how it can take on high-risk tasks and free up larger ships for more critical operations.

Herne’s ability to take on high-risk or routine missions autonomously is important as it allows navies to free up valuable crewed platforms, enabling them to focus on more complex and high-priority operations without overextending limited resources.

Before the demonstration, Charlie Adie, the System Design Authority, walked us around Herne, giving a first-hand look at its design. His explanations gave a clear sense of how much thought has gone into making the platform versatile and dependable for a range of missions, something I’ll dive into below. Pun absolutely intended.

Spending time with the team showed just how much dedication is behind Herne. It’s not just about building an autonomous underwater vehicle—the team are aiming to create tools that can make a real difference in how underwater missions are carried out.

This article explores the Herne project, its features, potential, and implications for future maritime operations. Now, first off and most important to remember, Herne is not positioned as a finished product but as part of a broader journey of development.

As Tim O’Neill explained during the demonstration, “This isn’t about us saying we’ve reached the end and we’ve got this operational capability. The point of what we’ve been doing…is about having a data point as to where we’re at…always validating that with the customer to ensure that actually, we’re still meeting a need.”

Trigger’s broom

Like the classic metaphor of “Trigger’s Broom,” where every part of a tool is replaced over time but it remains fundamentally the same solution, Herne’s design is built to evolve. While the core platform—the physical vehicle—may look consistent, it has been engineered for flexibility, allowing it to change and adapt as new technologies and requirements emerge.

The team explained how Herne’s modular payload bays, power systems, and software architecture are designed to be reconfigured and upgraded over time. This approach means that while the Herne of today is already capable, the Herne of the future will look very different, integrating advanced effectors, enhanced autonomy, and even entirely new mission types. BAE were keen to stress that Herne is more than just a vehicle—it’s a long-term solution that can keep pace with the ever-changing demands and, of course, budgets.

The payload bay

The two 2,500 litre payload bays are a standout feature, offering adaptability to meet various naval requirements. Currently, the system has two payload bays located at the forward and aft sections of the vehicle. These bays, effectively cube-shaped, are separated by the central housing for batteries and other essential electronics. Each bay is designed to operate independently, providing flexibility for multi-role missions. You can see the aft-payload bay in the cutout below.

However, this configuration is not fixed. The payload system can be reconfigured based on mission needs, with the two bays able to be combined into a single, extra-large payload bay at the front of the vehicle. This reconfiguration allows Herne to accommodate larger equipment, such as torpedoes or remotely operated vehicles (ROVs).

For example, integrating a Stingray lightweight torpedo or deploying an ROV for mine countermeasures becomes feasible with this expanded bay capacity.

Its payload bays are designed for quick swaps, making it possible to switch roles in operational settings with minimal downtime. O’Neill explained, “Undo four bolts, unplug two data connectors, and your payload’s out within an hour and a half on the dockside”. According to the development team, payloads can be swapped out in as little as 50 minutes to an hour and a half, even on a ship.

This means navies can rapidly prepare Herne for different tasks without significant downtime, whether it’s shifting from intelligence gathering to anti-submarine warfare or electronic countermeasures.

The core of Herne’s versatility

The Herne XLAUV’s autonomy is powered by Nautomate, a system designed to enable uncrewed vehicles to operate independently across a variety of naval missions. Developed by BAE Systems, Nautomate has been tested in above- and below-water environments.

A key feature of Nautomate, say BAE, is its flexibility. The system can be integrated into new platforms or retrofitted onto existing ones, allowing navies to upgrade older technology while incorporating modern autonomous capabilities.

During trials, Nautomate demonstrated its adaptability by guiding Herne through tasks like obstacle avoidance, intelligence gathering, and target tracking. This ability to operate in real-world scenarios highlights its potential as a tool for navies dealing with a range of operational challenges.

The system is designed to simplify the complexities of uncrewed operations. Its interface allows operators to plan missions, monitor progress, and analyse data with relative ease. By automating many tasks, Nautomate reduces the need for constant human intervention, enabling personnel to focus on broader strategic decisions rather than vehicle management.

According to literature from BAE Systems, Nautomate is also built with safety and security in mind, following international standards to ensure reliable operation in contested or high-risk environments. Features to protect against cyber threats and ensure mission resilience are integrated into the system, making it suitable for deployments in sensitive areas or alongside crewed platforms.

It is my view that Nautomate positions Herne as a flexible and adaptable option. While further development and trials are expected, the system’s performance so far suggests it could play a significant role in advancing the use of autonomous technologies in the underwater domain.

The mission

The live demonstration mission shown over the last week or so showcased Herne’s ability to perform reconnaissance missions autonomously.

For its initial demonstrations, the prototype was equipped with an Intelligence, Surveillance, and Reconnaissance (ISR) payload, featuring a mast with a electro-optical camera system. In the demonstration we were taken through, ISR capabilities were crucial for gathering and analysing information to support decision-making.

This payload allowed Herne to autonomously gather intelligence, such as capturing imagery of a cargo ship being loaded—potentially identifying activities like breaches of sanctions or supporting any number of mission needs where actionable intelligence is vital.

Nick Martin described the scenario to myself and other journalists, telling us that during the demo, Herne starts just outside the harbour, receives its mission, and dives covertly to enter the port. It autonomously plans its route, avoids hazards, and gathers intelligence. This is all achieved without operator input, demonstrating the autonomy built into the system.

Herne’s autonomy was further demonstrated through its machine vision system, which identified vessels using a database of thousands of images and flagged a simulated military cargo ship for further investigation. Nick elaborated, “It gave a 90% probability on an identified military cargo ship and flagged it for further investigation.”

Beyond reconnaissance, Herne demonstrated the ability to shadow vessels, autonomously tracking a rib to its destination before positioning itself 200 metres off the bow of the target to gather intelligence undetected.

Herne’s development timeline is also noteworthy, with the first dive achieved just 11 months after engineering began in September 2023. This rapid progress was facilitated by BAE Systems’ partnership with Cellula Robotics. Nick praised the collaboration, telling us that the companies went from concept to first dive in just 11 months and that this speed was only possible because of the close collaboration with Cellula Robotics.

“They bring deep knowledge in AUV design, and we overlay that with the military-grade systems and expertise that BAE brings to the table.”

This partnership highlights the advantages of combining commercial agility with military-grade rigor, enabling the rapid development of a platform tailored to modern naval needs.

Future development

The Herne project is far from finished. BAE Systems plans to refine the platform over the next 18 months, integrating features like hydrogen propulsion and enhanced stealth. O’Neill outlined the vision in simple terms, “In 18 months, we want Herne to be an operational, battle-ready capability”, which is pretty clear in how the company are pursuing the development of Herne.

This approach positions Herne as a key player in the future of autonomous naval operations, ensuring the platform remains aligned with evolving military demands. The platform’s adaptability extends to its propulsion system. While the current version uses batteries, future iterations will incorporate hydrogen fuel cells, enabling a range of up to 5,000 kilometres.

O’Neill also highlighted the scalability, telling us that if a navy needs eight to nine days of endurance, they can configure it with lithium-ion batteries. If they need longer range, they can integrate hydrogen fuel cells, the firm is aiming the product to the buyers need, providing the capability they need without overengineering.

Additionally, Herne’s design allows for flexible deployment from surface ships, submarines, and even air delivery via heavy-lift helicopters, ensuring it can operate globally in diverse environments. We were told that it could even be dropped from an A400M or launched from a Type 26 Frigate.

In the next 18 months, BAE Systems plans to integrate an array of cutting-edge effectors to enhance Herne’s operational role. These capabilities will transform Herne from an intelligence-gathering platform into a multi-role system capable of addressing a wide range of underwater threats.

The following effectors are expected to be deployable:

Archerfish Mine Disposal System. Proven in service, this system is designed to counter the threat of increasingly sophisticated and resistant modern mines.

Its compact and portable design makes it deployable from ships, helicopters, small boats, and uncrewed vehicles like Herne, adding significant versatility to naval mine countermeasure operations.

Next Generation Depth Charge. This small, lightweight depth charge offers enhanced performance for tackling shallow water threats.

Its integration with both crewed and uncrewed platforms, including Herne, ensures its effectiveness in dynamic and constrained environments.

Kingfisher Stand-Off ASW Effector. This system delivers depth charges, sonar, and other countermeasures from a naval gun onboard a warship.

Its ability to operate in anti-access and area-denial environments complements Herne’s role in providing persistent, rapid, and cost-effective underwater responses.

Sting Ray Lightweight Torpedo. Designed for precision and effectiveness in underwater combat, this lightweight torpedo represents a significant upgrade to Herne’s offensive capabilities.

Its deployment via a reconfigured payload bay would allow Herne to conduct targeted anti-submarine warfare operations autonomously.

How much?

O’Neill stressed the affordability of Herne relative to existing autonomous platforms, highlighting the intent to make Herne accessible to navies with budget constraints. He notes that some large platforms can cost hundreds of millions of dollars and emphasised that Herne is designed to provide combat mass without the financial burden of gold-plated systems, telling me, “We’ve tried to embrace costs and not gold plate it… to deliver value for money.”

Beyond the financial cost, the system is designed to be attritable, it can be lost without human cost. “An autonomous platform needs to be expendable,” O’Neill explained.

“At the moment, how navies operate, their assets are precious… In an operational sense, they need to be able to go up threat, take more risk if necessary, and get the job done without those traditional fears of ‘what if we lose it?'”

This expendability is balanced with strategic value, allowing Herne to undertake high-risk or high-endurance missions that would otherwise require crewed assets.  As O’Neill highlighted, “Whether it’s ASW in the North Atlantic or ISR in contested waters, Herne increases coverage and operational capacity while freeing up crewed platforms for tasks they excel at.”

Healthy interest

Herne has attracted significant interest, with representatives from over ten navies attending the harbour demonstration. These included NATO and non-NATO nations. “This is not a classified project. We want this to be available to all, with national caveats based on how they configure and use it,” O’Neill advised

Feedback from navies highlighted diverse requirements, from sprint speeds for high-tidal areas to long-range covert missions. This feedback is critical as BAE Systems continues to refine the platform to meet these varied needs. As navies grapple with budget constraints and increasing demands, BAE has positioned Herne as a long-term, affordable and practical solution.

Its hoped-for ability to provide combat mass, deploy effectors, and gather intelligence autonomously reduces the burden on traditional assets while enhancing operational flexibility. O’Neill summarised its potential, telling us, “We’re not just building a vehicle; we’re building a capability that evolves with the needs of the operational landscape. Herne offers navies the tools to do more, take more risks, and achieve their missions in ways that weren’t possible before.”

While its full potential obviously remains to be seen, and 18 months can certainly be a long time in the industry, the platform offers a glimpse into the future of autonomous naval operations should the course be stayed.