MUM, World’s Largest UUV, to be Built in Germany

The latest Unmanned Underwater Vehicle (UUV) designs, being introduced in the United States, Britain, China and elsewhere, are several times bigger than most mainstream models already in service. Now German shipbuilder Thyssenkrupp Marine Systems (TKMS) is preparing to start construction of their “MUM” underwater drone. The German MUM (Modifiable Underwater Mothership) will be the largest autonomous underwater vehicle in the world. In TKMS terms this a ‘flat fish’ type design.
Potential roles include offshore services such as inspection, maintenance and repair. It can also aid exploration offshore oil and gas fields, or marine minerals. It could take core samples via a drill, or support seismic surveying. MUM could also support law enforcement or inspect strategic national infrastructure. This is UUV with a modular structure that will be able to take on many different tasks in the civil sector for the exploration and use of the world's oceans. Surveillance and inspections of underwater cables are also likely. TKMS has played it close to the vest on key specifications.
What we know:
-A unique concept, MUM is both longer and twice as wide as any publicly known UUV design.
-MUM is powered by hydrogen fuel cells and lithium-ion batteries, a form of air-independent propulsion.
-This will generate around 80 kW nominal power and will be supplemented by lithium-ion batteries for peak loads.
-This is sufficient to haul a significant payload and power sensors and two counter-rotating screws (propellers).
-The counter-rotating propellers are driven by a fuel cell motor
-The inner hull is constructed out of modules which, according to Naval News, have the same dimensions as 10 or 20 foot shipping containers
-MUMM can operate continuously at depths down to 5,000 meters for several weeks at a time.
-The XLUUV is composed of configurable base and mission modules that are enclosed by a hydrodynamic casing.
-The vessel’s width allows the sail, which is itself modular, to be mounted on the UUV’s side.
-Mum has a payload capacity of several tons.
-It can operate in an environmentally friendly manner in ecologically sensitive regions.
What we don’t know:
-MUM's range
-Specific payload options
-Planned onboard sensors such as synthetic aperture active or passive sonars
-Quieting features

Thanks to CDR David Place (USN/Ret), davidplace47[at]gmail[dot]com, and Robin E. Alexander, President ATC, alexander technical[at]gmail[dot]com, for their assistance with this report, the background for which appeared in # 23 - 2 - 13 FEBRUARY 2023 edition of the UNMANNED SYSTEMS NEWS (USN). Special thanks, also, to CAPT Julio Gutierrez (USN/Ret) for sourcing this article and for sharing his observations.

David distributes the USN, a free, comprehensive newsletter in PDF format every week or two, as well as serial news flashes, from which this NREF news update was sourced. To be included in his distribution, simply send a subscribe request to davidplace47[at]gmail[dot]com.