Thales has given new insight into Sonar 76Nano, a compact tile based sonar system developed to support the Royal Navy’s push toward distributed and uncrewed underwater sensing.
The company briefed UK Defence Journal on the prototype following a rapid ten month development cycle linked to emerging requirements within Project Cabot and the wider Atlantic Net and Bastion concepts.
According to Ian McFarlane, Sales Director for Underwater Systems at Thales UK, the idea behind 76Nano began to take shape about eighteen months ago. The company had observed a shift in Royal Navy anti submarine warfare activity. As McFarlane put it, “the usage was going up. The operational tempo was increasing” while the number of major platforms was falling. This created an obvious question: “How we fill this gap?” Thales concluded that the answer was a new kind of sensor that could operate from uncrewed platforms and static seabed nodes rather than rely on a shrinking fleet of high value hulls.
A central feature of 76Nano is its tile based architecture, which replaces fixed flank arrays with modular acoustic panels. Each receive tile measures seventy five centimetres square, and the active transmit tile is a forty centimetre square unit. These can be arranged around curves or assembled into larger panels depending on the host vehicle’s geometry. McFarlane likened the concept to tiling a wall and stressed that aperture and frequency coverage scale with tile count. Lower frequencies travel further underwater, so adding tiles increases detection range and improves signal robustness. Thales has engineered the tiles to butt together with a flush finish to minimise drag and simplify integration. The onboard electronics recognise the number and orientation of the tiles and fuse all returns into a single coherent sonar picture. Depending on UUV size, arrays can range from a handful of tiles on a compact node to roughly forty eight per side on a large vehicle, which, in McFarlane’s view, could approach SSN like sensing performance in environments such as the Baltic.
Thales says the tiles are designed to minimise impact on space, weight and power, a key consideration for uncrewed platforms with limited margins. While layouts vary by vehicle, the company described a typical array as comprising around thirty six receive tiles, for example arranged in a three by twelve configuration along a vehicle’s flank. Larger UUVs could carry more, while smaller platforms would use fewer tiles, allowing operators to scale sensing performance to platform size and mission need without redesigning the system.
McFarlane expanded on that point, saying that a medium or large UUV fitted with about forty eight tiles per flank would, in Baltic conditions, offer “almost the same capability as an SSN” and, in deeper Atlantic water, “better than two thirds as good as an SSN”. He however framed these comparisons in terms of physics and environmental assumptions, which play a major role in long range detection. He also pointed to cost and risk. A nuclear submarine is a multibillion-pound asset. A large UUV carrying this sonar would be far cheaper to field, easier to deploy covertly, and carries less operational consequence if lost. McFarlane argued that this differential supports the case for distributed uncrewed sensing alongside the existing fleet.
The system provides passive listening, active ASW, synthetic aperture imaging, and subsea communications in a single package. The active mode uses a narrow band ping designed for low probability of intercept. The receive tiles are built to interpret weak returns and also support acoustic communications. McFarlane described the transmit function as “a narrow band directional ping” that allows “transmit comms out” and reception of acoustic retasking signals. The synthetic aperture mode gives seabed imagery for infrastructure monitoring or environmental survey.
Distributed sensing depends on density and placement rather than a single perfect array. When asked how many nodes are needed, McFarlane resisted a fixed number and tied it to concepts of operations. In a choke point, “one or two will be absolutely sufficient” for persistent passive listening. In the North Atlantic, a handful operating alongside SSNs could offer forward cueing. For wide area networks like Atlantic Bastion, he noted earlier estimates requiring hundreds of gliders but suggested higher quality UUV sensors might reduce that mass requirement.
The direction mirrors the First Sea Lord’s recent emphasis on accelerating delivery and expanding uncrewed mass within a hybrid fleet. He has argued that maintaining credible ASW coverage with fewer major platforms will require distributed sensing and faster industrial cycles. That theme shaped discussion at the Sea Power Conference, where urgency was repeatedly stressed. Thales echoed that mindset during the briefing. McFarlane characterised the ten month development sprint as a response to that demand for pace and remarked that, if a customer were ready to proceed, “I’ll take the order today”. The company is clearly presenting 76Nano as the type of quickly fielded sensing mass that senior leadership says will be needed.
Integration was a recurring theme. Thales is not a UUV builder, which shaped the design philosophy. The tiles can be arranged around curves or assembled into different rectangles. The onboard electronics understand the orientation and number of tiles and fuse the data into a single sonar picture. This avoids presenting multiple disjointed feeds and supports both ASW and synthetic aperture modes. McFarlane said several unnamed UUV designers have shown interest. From their perspective, UUVs are often “subsea trucks” that carry payloads rather than generate capability themselves. A low drag, low power sensing package widens their utility.
Testing has been carried out at a Ministry of Defence acoustic facility. Thales used calibrated sources to verify that the tiles detect signals with the expected strength, direction, and frequency. McFarlane said, “the answer to that is yes, we are” when asked whether the prototype meets expected technical performance. The same method was used to test the active transmitter. Sea trials will follow once tiles are arranged on a host platform.
The prototype is expected to make its first public appearance with the Royal Navy later this month as part of a technology demonstration event. Thales says the demonstration will allow naval personnel to assess the system’s capabilities directly and engage with engineers involved in its development. While the event does not signal a procurement decision, it forms part of the wider effort to explore how rapidly developed sensing technologies might support the Navy’s emerging uncrewed and distributed concepts of operations.
The AI component of the system focuses on triage rather than autonomy. As data volumes have risen across successive submarine classes, operator overload has become a risk. McFarlane explained, “There’s too much there to physically understand.” The AI sorts acoustic returns, highlights items of likely importance, and acts as a filter to suppress clutter. It also supports post-mission analysis by identifying patterns or signals that might otherwise be missed. Thales frames this as cognitive assistance rather than a replacement for operator judgment.
Sovereignty is a concern for the UK, and Thales says most of the system is UK built, with some components sourced from partner nations as with 2076. The active transmitter involves Neptune Sonar, a British SME. Thales retains design rights and can license production to allies as required. McFarlane said, “We’ve tried to keep as much of it as possible within the UK.”
When asked directly what problem 76Nano is intended to solve, McFarlane offered a clear summary. “This solves the problem of getting enough fidelity in your ASW solution” while also supporting seabed infrastructure tasks. The modular tile concept allows UUVs to carry more sensing power than previously practical. “The more tiles you’ve got, the better fidelity, the better the further out you’ll see.” That logic fits the Royal Navy’s interest in distributed sensing and hybrid fleets.
