Sweden’s Saab Successfully Fires Lightweight Torpedo from CB 90 Craft and Unmanned Surface Vehicle

In a major step toward enhancing the versatility of small naval platforms, Swedish defense company Saab, in partnership with the Swedish Defence Materiel Agency (FMV) and the Swedish Armed Forces, has successfully conducted test firings of its Lightweight Torpedo (Torpedo 47 or SLWT) from both a CB 90 fast assault craft and an Unmanned Surface Vehicle (USV). These trials mark a significant achievement in adapting advanced anti-submarine warfare (ASW) weapons to smaller and more agile platforms.

The main aim of the trials was to explore the feasibility of integrating the Torpedo 47 into smaller vessels than those it was originally designed for. Saab confirmed the torpedo was mounted temporarily, indicating this is still an experimental capability—but one with promising operational potential.

CB 90: From Assault Craft to ASW Platform

The CB 90, widely used by the Swedish Navy for rapid troop transport and coastal patrol, has traditionally employed depth charges for underwater threats like divers or midget submarines. These earlier ASW tactics relied heavily on external sensors to locate targets.

However, in the recent trials, the CB 90 was fitted with two single-tube launchers on its stern to fire the SLWT. The test firings showed that the CB 90 and SLWT work “very well” together, hinting at future integration of this ASW capability. While not yet part of a formal operational program, these successful tests could lead to the CB 90 being used as a torpedo-launching vessel in the future.

Torpedo 47 (SLWT) – Key Specifications

• Type: Lightweight Anti-Submarine Torpedo

• Length: Approximately 2.85 meters

• Weight: Around 340 kg

• Warhead: High explosive, approximately 50 kg

• Guidance System: Wire-guided with active/passive sonar homing

• Range: Estimated 20+ kilometers

• Speed: 40+ knots

• Target: Submarines and underwater threats in coastal and littoral waters

Designed for flexibility, the SLWT can be deployed from submarines, helicopters, surface ships, and now—demonstrably—from small boats and unmanned vessels.

USV Launch with MARTAC’s T24 Devil Ray

In addition to the CB 90 trials, Saab also conducted test firings of the SLWT from a T24 Devil Ray USV, developed by American firm MARTAC. This unmanned vessel was equipped with a single torpedo launcher, making it a lightweight and unmanned solution for future ASW missions.

The inclusion of the USV in these tests reflects a broader trend in modern naval warfare: integrating autonomous and remote-controlled systems to reduce risk to human crews while maintaining or even enhancing combat effectiveness.

Swedish Marines and the Amfbat 2030 Programme

The tests align with Sweden’s ongoing Amfbat 2030 modernisation programme, which aims to improve the Swedish Marines’ ability to engage threats directly from small boats, rather than relying solely on land-based operations. Adding torpedoes to the CB 90’s mission set could significantly boost the marines’ ability to operate in the shallow, island-filled waters of the Swedish archipelago.

What’s Next?

Though not yet confirmed for deployment, the successful tests have opened the door to expanding the Swedish Navy’s ASW capabilities through smaller and more flexible platforms. The Armed Forces and FMV are now analyzing the results to determine how best to move forward.

As Saab owns both the CB 90 design (after acquiring the Dockstavarvet shipyard in 2017) and the Torpedo 47, the company is uniquely positioned to develop a fully integrated, export-friendly ASW package for navies looking for compact and networked anti-submarine solutions.

Whether onboard crewed boats like the CB 90 or future fleets of autonomous USVs, Saab’s lightweight torpedo system is showing that big firepower can now come from small platforms—a major evolution in coastal and littoral naval defense.