Challenge
Traditional submarine-hunting sonar systems were deployed from large frigates. Powerful in deep oceans, but nearly useless in harbors, shallow coastal waters, or narrow fjords where maneuvering is impossible. And not every navy can even field such ships: countries in Asia and South America often lack the budget, crew, or infrastructure for billion-euro warships. To close the gap, they turn to unmanned surface vehicles (USVs) carrying compact sonar systems. The challenge: cable fairings and cables take up significant space, so designs must shrink dramatically while still delivering defense-grade strength, fatigue resistance, and flawless sonar data transmission.
Solution
A key hurdle was compactness: traditional cable fairings, which streamline the hydrodynamics of towed arrays, add bulk and limit deployability on small USVs. The cable had to be slimmer, lighter, and better integrated, yet uncompromising in performance. Instead of “building to print,” the project began with a detailed specification phase. Our defense client provided extensive functional requirements (electrical, mechanical, and environmental), including tensile strength, vibration resistance, and survivability in saltwater, humidity, and even aggressive chemicals.
The engineering team translated these requirements into a Design Compliance Matrix, mapping each demand to a verification method: analysis, inspection, or full-scale testing. Complex calculations addressed helical geometry, fatigue life, elongation, and abrasion resistance. Where modeling fell short, such as repeated launch-and-recovery cycles across rollers and sheaves, rigorous testing validated durability.
Critical design reviews locked the configuration before production, while keeping room for iteration if test results revealed new risks. The final custom cable design combined multiple power and telemetry conductors, drain wires, shielding, and armor into a torque-balanced geometry. Compact enough to fit USVs without bulky fairings, yet strong enough to deliver high-resolution sonar in the harshest conditions.
Result
The result was a sonar tow cable system compact enough to operate from small unmanned surface vehicles. By combining compact design with military-grade ruggedness and full compliance, DeRegt proved that advanced sonar capability can be both accessible and scalable. Democratizing coastal defense for navies with very different budgets and operational needs.
Expert view
“We downsize sonar cables without shrinking performance. Or lifetime.”
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