From Challenge to Change: How our engineers rewrote the rules of submarine stealth

Submarines are and will remain a key national security asset. They rely on stealth to execute essential operations such as deterrence and rapid response, while remaining undetected. However, as sonar and surveillance systems rapidly evolve, improving the acoustic performance of components and optimising the submarine's acoustic signature matters more than ever.

In this article, we explain how a single question, raised during a discussion at an industry event in Japan, led to a significant worldwide collaborative project. This project, which evolved as part of our Growth Hub incubator process, resulted in Acoustic Control Vantage™, a breakthrough technology in terms of submarine stealth. Our approach throughout was simple, centred not on refining what already existed but redefining what was possible.

At Japan’s first DSEI event in 2019, IMI showcased a compact, shock-resistant double ball valve, an inherently quieter, more resilient alternative to many traditional solutions. It made a strong impression on customers at the event, and, as a senior leader of the Japanese Navy commented, ‘This is good, but can you make it even quieter?’

That question helped reframe the entire problem. As Rob Taylor, IMI Marine’s Technical Director, recalls: “We realised we had an opportunity to be at the cutting edge of marine valve innovation and to influence system-level acoustic challenges. That moment changed everything.”

Our Growth Hub initiative empowers engineering, commercial and other leads to engage directly with customers. Not to pitch, but to listen to real customer problems. Growth Hub teams often begin conversations by asking potential partners what their most pressing problems are. This approach revealed the need for quieter components and a new way to manage signature profiles across submarine systems. Drawing on our torturous path technology, initially developed for entirely different industries, the team began exploring how it could be reimagined to meet the unique demands of naval stealth.

The ACV™ project took shape during the COVID-19 global pandemic, when remote collaboration became the norm. Engineers from Japan, France, the USA, the UK, and beyond worked together to design, prototype, and test solutions using acoustic chambers and 3D-printed components.

Export restrictions led our team to develop an in-house additive manufacturing process, tailored for naval applications. It proved to be a turning point. ‘It was an inspiring collaborative process,’ Rob Taylor recalls, ‘We had experts from a range of technical disciplines to work with worldwide, and it proved to be an enriching experience for us all.’

Fully patented in 2024, we launched the result, Acoustic Control Vantage™, as an additive-manufactured trim solution that could reduce fluid-borne noise. Its impact goes beyond stealth and improves current and future platforms' availability, reliability, and maintainability. ACV™ also limits the cavitation effect, resulting in reduced component erosion, seal wear and maintenance costs. Crucially, the technology can manipulate signatures to reduce the likelihood of detection and be successfully deployed across systems manufactured by both IMI and other manufacturers. In that sense, it’s not just a flow control solution; it’s a stealth-enabling innovation that improves fleet availability.

ACV™ is now undergoing platform trials with several navies and, in some cases, full technology adoption. It has been featured at major international events and is an example of additive manufacturing innovation for naval applications.

Recent trials in advanced underwater testing environments have shown impressive results, reinforcing ACV’s potential to reshape acoustic control in submarine systems. As awareness builds, so does momentum, with more defence stakeholders exploring its strategic value.

For our engineers, innovation isn’t about features but outcomes. “We’re driven by mission success,” adds Rob. “ACV™ is an example of how we fuse human insight and advanced technology. A quiet power in action.”

The project has earned internal accolades, including the IMI Innovation Award. However, its value lies in its potential as a key enabler of strategic national defence capabilities. Quite simply, ACV™ improves fleet availability and safety at sea. It demonstrates how we combine deep expertise, smart technologies, and long-term partnerships to deliver lasting value for our customers.

Acoustic Control Vantage™ represents more than a technical breakthrough. It’s a new benchmark in defence innovation. It proves what’s possible when engineers listen first, collaborate widely, and design purposefully. It confirms our belief that understanding the customer problem gives us our competitive advantage and enables us to create practical solutions at pace.

As navies worldwide seek new ways to stay ahead of detection and improve platform availability, reliability, and maintainability, ACV™ offers a powerful solution to the undersea stealth question, which began with a single challenge and resulted in a quiet revolution.

Explore how IMI uses advanced additive manufacturing to push the boundaries of acoustic control and more.