Extra large uncrewed underwater vehicles (XLUUVs) are quickly becoming a major trend in naval warfare. Leading navies have initiated programs to develop and explore these. Currently, the U.S. Navy and Royal Navy appear to be in the lead, both in experimentation and in orders.
In Europe, we have recently seen XLUUV project in France and Germany. In Asia, we previously reported that both South Korea and China are also working on such large underwater drones. At the DSEI Japan 2023 held earlier this month near Tokyo, ATLA was showcasing for the first time its own XLUUV project. The Japanese MoD’s agency calls it officially a “Long endurance, multi role UUV research prototype”.
The XLUUV is modular, therefore its size depends on the mission modules: The length of the “main body module” is 10 meters, and the notional length of the UUV with a mission module is 15.6 meters. The diameter is 1.8 meters. The propulsion system and configuration is unusual with four directional thrusters. This is something usually found on smaller UUVs for inspection of mine neutralization, it likely provides better maneuverability to the XLUUV. Mitsubishi Heavy Industries (MHI) is the main contractor.
According to ALTA, the key drivers for the XLUUV project are:
- Long distance deployment with high reliability, resilience and survivability under the circumstances where support by surface ships is unavailable.
- Adaptability to a wide variety of operations such as ASW, ASuW, mine warfare, ISR, electronic warfare etc.
The goal of the project is to demonstrate that the XLUUV can perform “autonomous navigation with improved reliability and environmental adaptability by AI” and that it can fulfill “various kinds of missions by replacing mission modules (both hardware and software)”.
Naval News regular contributor and submarine expert H I Sutton shared his thoughts about this new project with us:
Japan is already at the forefront of applying new technologies to submarines. The JMSDF has been the first to fit lithium based batteries aboard operational boats. This lends the XLUUV project a lot of credibility.
With the payload module the vehicle will be almost 16 meters long, placing it well within the extra-large category of underwater drones. The payload module also points to future versatility.
ATLA mentioned a fairly large array of mission sets for the XLUUV. What exactly the payload is, we are kept guessing. But it’s potential to be armed, and play a vital role in Japan’s future defensive capabilities are clear.
According to ATLA, the modularization of the UUV (hull design, hardware and software architecture and interfaces) will be opened to the public in order to accelerate this R&D project for both defense and civil applications.
According to Dr. Horie, Director General of the Technology Strategy Department at ATLA, the battery pack of the XLUUV is also modular depending on mission requirement and features Lithium Ion technology. Here is our interview with Dr. Horie on the XLUUV project:
The “Long endurance, multi role UUV research prototype” project was in the manufacturing phase between 2019 and 2022. Suppliers and partners (including civil ones) for the modularization will identified this year, as well as the manufacturing of a payload delivery module. Performance tests and sea trials of the XLUUV started this year and are set to last until 2025.