The development of an LDUUV heralds a bold step
forward for the Navy. The vehicle, which does not have
a defined length and weight yet, as NUWC’s concept
still is early in development and its fielding could result
in a major shift in how the Navy conducts its underwater operations, said Bryan Clark, a senior fellow at the
Center for Strategic and Budgetary Assessments. While
the LDUUV will be launched and recovered from a
Virginia-class submarine via a payload module, the Navy
possibly could launch the vehicle off a surface ship, like
an expeditionary fast transport, he added.
“The target they’re [the NUWC] aiming for is to get
endurance of up to a month or maybe two months,”
Clark said. “They would use it to do surveillance
missions. It would have passive sonar or active sonar,
maybe a towed array sonar, and they would use it for
that kind of surveillance mission.”
The LDUUV would have a side-scan sonar that
could be used to survey the bottom of the ocean in
places and do it without the enemy knowing it was
there. Today, a manned submarine would have to con-
duct that operation.
The LDUUV also could deploy its own payloads, such
as acoustic sensors and hydrophones that would drift
to the bottom and listen up into the water column. The
vehicle would be able to deploy things in areas that could
not be reached by surface vessels or even a submarine.
But there are complications: as big as it is, the LDUUV
is not large enough to carry its own diesel engine, so it
will rely on batteries and fuel cells.
“There’s only so much you can put in in terms of payload and batteries,” Clark said. “So how long it can operate on its own is going to be constrained by how big it is.
So the endurance is constrained to one to two months.”
The LDUUV also is a big vehicle, and its deployment
and recovery will be difficult to conduct clandestinely.
“The Navy has got to think through what the CONOPS
[concept of operations] is if they do that,” Clark said.
“That may constrain the number of opportunities to use
it. If you wanted to do a two-week operation, it can’t take
more than a week to get there, and if it only goes 5 knots,
it constrains you to 300 to 400 miles away.”
Still, it is a big improvement over how the Navy currently does things, which involves sending a manned
submarine or a less-reliable UUV to do the job. This
larger UUV will allow the Navy to send in bigger sensors and stay on station for longer than it could in the
past with other UUVs.
The Navy has set aside some money in the most
recent budget to pursue a larger UUV that would be
capable of carrying a diesel engine, which could extend
its endurance out to six months. The current LDUUV
effort at NUWC still is in its infancy and not yet funded
Contractors themselves are getting in on the action
and designing similar UUVs — for example, Boeing’s
“We can build pretty big unmanned things, and now
the Navy is looking to buy a few of them to figure out
how to exploit them,” Clark said. n
The Office of Naval Research unveiled its Large Displacement Unmanned Underwater Vehicle (LDUUV)
Innovative Naval Prototype in April 2015. Naval Sea
Systems Command is working on a concurrent LDUUV
project, with Naval Undersea Warfare Center Newport
Division, R.I., as the project lead.