HII wins DIU contract to deliver Torpedo Tube Launch and Recovery System

A new contract to HII for its Torpedo Tube Launch and Recovery (TTLR) system, which enables REMUS UUVs to be launched from a torpedo tube, could extend submarine sensor reach. This may be a strong example of manned-unmanned teaming.

By Sam Cranny-Evans, editor of Calibre Defence, published on April 29, 2026.

HII (NYSE: HII) has been awarded a contract for its Torpedo Tube Launch and Recovery (TTLR) system. The system is designed to enable REMUS unmanned underwater vehicles to be launched and recovered from a submarine’s torpedo tubes.

Announced by HII on April 27, the contract was placed by the US Defense Innovation Unit (DIU). The DIU’s mission is to accelerate the US Department of War’s adoption of technologies that could deter and win a war. So, this may indicate that the TTLR could be on an accelerated path into service.

REMUS is a UUV deployed by more than 30 nations for underwater intelligence, surveillance and reconnaissance. It carries side-scan sonar and is often used for mine-counter measures and anti-submarine warfare (ASW).

This DIU contract builds on two demonstrations of the TTLR in 2025:

USS Delaware, June: The Virginia class submarine embarked a UUV squadron and conducted three autonomous launch and recovery sorties overseas. It used the REMUS 600.
Virginia class submarine torpedo tube, July: The US Navy’s Undersea Warfare Center in Newport completed recovery of a REMUS 620 from a Virginia class torpedo tube. This test was conducted using a shutterway test fixture in Senecca Lake, New York.

Of note, HII and Babcock signed an MoU in 2025 to work on integrating REMUS into Babcock’s Submarine Weapon Handling System. That agreement indicates there is wider interest in submarine-launched UUVs and systems like the TTLR.

Tech profile: REMUS 620

A REMUS 620 UUV from HII, which can be launched from the Torpedo Tube Launch Recovery System (TTLR). Credit: HII

There are several REMUS variants, the 620 mentioned above is designed to provide long-range reconnaissance. With a reach of 275 nautical miles (509 km) and endurance of 110 hours, it can significantly expand the sensor range of a submarine. The length and specifications vary with its mission payload, but they can be up to 5.2 metres long, weighing in at 362 kg. The UUV can dive to depths of 600 metres, and travels at 8 knots using its electric motor and propeller.

It can be equipped with acoustic communication systems, which would enable it to pass limited quantities of data back to a submarine whilst submerged. It also carries a radio frequency antenna for radio communication and recovery. An array of navigation tools, including GPS and a very accurate inertial navigation system empower its autonomous patrolling while submerged. The inertial navigation is provided by iXblue, which is a specialist in the field of laser ring gyroscopes amongst other things.

The sensors are understood to include side-scanning sonar, tools for hydrographic surveys, and even electronic warfare.

Calibre comment: Manned-unmanned teaming for submarines

The recent analytical focus across the defence community has been on uncrewed platforms. This is understandable given the use of USVs and drones in the Middle East and Ukraine. However, there is need for balance within the analytical community. For example, the recent sinking of Iran’s Iris Dena frigate – and Operation Epic Fury in general – should reinforce the close to irreplaceable role of conventional platforms. That event should serve as a reminder of how hard it is to replicate the lethality of a heavy weight torpedo deployed by a submarine that is very difficult to detect and track.

With this in mind, there is a lot of value in enhancing the capabilities of conventional platforms. In this case, adding the TTLR to Virginia class submarines would significantly extend their ISR range. This is important for finding targets as well as avoiding ASW forces. Furthermore, hunting vessels like attack submarines is likely to be a high priority for US and NATO adversaries. Successful ASW can limit a country’s options or willingness to accept risk, especially if those submarines carry nuclear weapons.

In a nutshell, the manned aspect of manned-unmanned teaming should be the centre of analysis and assessments when it comes to integrating uncrewed platforms into a force. The most important element is what the unmanned elements enable the manned elements to do. This should go without saying, but a lot of focus goes into the capabilities of the unmanned platforms as if they exist in a vacuum.

The lead image shows a REMUS UUV on the TTLR. Credit: HII.