L3Harris Technologies has received a contract from the US Defense Innovation Unit to deliver its Torpedo Tube Launch and Recovery (TTLR) system, which deploys and retrieves autonomous underwater vehicles (AUVs) through existing submarine torpedo tubes without the submarine needing to surface or expose personnel to risk.

The system deploys and retrieves the company’s Iver4 900 AUV and has been validated by US and allied navies for intelligence, surveillance, reconnaissance, mine detection and seabed warfare missions. The TTLR launcher and multiple Iver4 900 AUVs will be built at L3Harris’s Fall River, Massachusetts facility. Neither contract price nor duration has been disclosed.

The engineering significance of the TTLR lies in its use of existing submarine infrastructure. The modular system is compatible with both attack and ballistic submarine classes and multiplies force capacity from existing hulls without requiring new construction. It also delivers the first US Navy submarine and aviation-approved AUV lithium-ion battery technology, enabling longer-duration missions with hot-swap capability for continuous operations. NiMH cells provide a range of 40nm over 20 hours, while lithium-ion packs extend that to 80nm over 40 hours.

The Iver4 900 itself is a compact vehicle around 2.5m long, with a titanium and carbon-fibre pressure housing rated to 300m depth and a weight of under 104kg, dimensions that allow it to be handled through a standard torpedo tube. It carries modular payload bays typically equipped with dual-frequency side-scan and bathymetric sonars, with navigation provided by an inertial and DVL suite, surface Wi-Fi and Iridium communications, and an acoustic modem for subsurface use.

The TTLR’s interoperability across multiple submarine classes and allied platforms advances the US Navy’s manned-unmanned teaming vision and supports AUKUS Pillar 2 collaboration between the US, UK and Australia.

The UK operates the related Iver4 580 for unmanned minehunting and survey operations, underlining the system’s relevance to allied navies including the Royal Navy.

STATS: IVER4 900 is a compact autonomous underwater vehicle around 2.5m long, with a titanium and carbon-fibre pressure housing rated to 300m depth and a weight of under 104kg.

This article appeared in Technical, TNA May/June 2026.