USA and the UK Test Launch of the Mk 48 from the XV Excalibur Underwater Drone

The U.S. and British navies successfully tested the launch of a Mk 48 heavy torpedo from the British unmanned underwater vehicle XV EXCALIBUR.

The U.S. Navy reported this.

The tests took place on September 13 at the British underwater testing facility BUTEC in Scotland.

During the tests, a U.S. Mk 48 heavyweight torpedo was launched from a British unmanned underwater vehicle. This allowed for testing the mechanical, electrical, and software compatibility of the U.S. weapon with the British autonomous platform.

The tests were conducted as part of the Broadsword project and the Trial Iron program, which are being implemented under the second pillar of the AUKUS defense partnership. Their goal is to integrate the partner nations’ weapons and control systems with unmanned platforms, in particular to create new strike capabilities for the submarine fleet.

The U.S. Navy’s Rapid Capabilities Development Office, the Defense Innovation Unit (DIU), the British Royal Navy, the Naval Undersea Warfare Center (NUWC) Keyport, and industry partners have joined the effort.

According to the Chief of Naval Operations of the U.S. Navy, the tests confirmed the ability to deploy U.S. weapons from British submarines.

This interoperability is intended to enable more flexible use of joint forces and expand the allies’ combat capabilities.

The next phase will be the CUTLASS project, which plans to utilize the Anduril Dive-XL large autonomous underwater vehicle. The program calls for further integration of weaponry, improved command and control systems, and the development of tactical scenarios for using unmanned underwater vehicles.

XV Excalibur

Militarnyi previously reported that the Royal Navy of the United Kingdom had received the XV Excalibur—a large unmanned underwater vehicle developed by the British company MSubs. It is 12 meters long, 2 meters wide, and has a displacement of 19 metric tons.

The XV Excalibur was created as an experimental platform for testing autonomous underwater technologies. The vehicle is designed to perform reconnaissance missions, integrate various payloads, and interact with manned submarines.

It was officially presented in May 2025, after which a sea trial program lasting approximately two years began.