Unmanned underwater vehicles (UUVs), sometimes known as underwater drones, are any vehicles that are able to operate underwater without a human occupant. These vehicles may be divided into two categories, remotely operated underwater vehicles (ROVs), which are controlled by a remote human operator, and autonomous underwater vehicles (AUVs), which operate independently of direct human input.
Unmanned underwater vehicles are now being used across the battle space. Dr Gareth Evans takes a close look at the evolving technology to discover what the future holds. "Unmanned underwater vehicles (UUVs) have been on the inventories of navies around the world for decades, chiefly being used to provide targets for anti-submarine training exercises, but more recently, recognition has been growing of the wider potential of UUVs in the battle space."
Encompassing everything from the older remotely operated vehicles (ROVs) and remotely operated towed vehicles (ROTVs) to the latest generation of autonomous underwater vehicles (AUVs), the technology sits poised to be a key enabler for naval littoral operations and an essential component of future network-centric warfare.
Developing a greater military role has undoubtedly been on the strategist's wish-list for some time, but it is only now that the principal enabling technologies have advanced sufficiently to bring the broad range of applications envisaged within the realm of the possible – and it is a trend that is gathering pace.
In their 2008 presentation to the International Naval Engineering Conference, Tim Hardy and Gavin Barlow of BMT Defence Services predicted that "an increasing proportion of future AUV research and development activity will be focused on meeting requirements that have more of their basis on rapidly expanding military and homeland security markets."Unmanned underwater vehicles have been on the inventories of navies around the world for decades."
Today, companies such as iRobot – the firm behind the successful development and commercialisation of the Seaglider long-range, high endurance UUV, which is itself in service with the US Navy – are actively working on transitioning such research prototypes into viable products.
"This includes Ranger," says Tom Frost, programme manager, Maritime Systems at iRobot, "a man-portable UUV that supports technology development related to homeland defence, mine warfare, underwater surveillance / reconnaissance and other missions. Ranger is easily launched and recovered by a single user from a small inflatable vessel, ship or the shore."
To help provide some of the required capabilities in the interim, they are also developing two high-speed AUVs for the US Office of Naval Research, as part of the future naval capability (FNC) programme. One of these, MATC – mobile acoustic torpedo countermeasure – is designed for deepwater use to protect submarines from torpedo attack, closing with the inbound threat and emitting signals to confuse it and draw it away.
The other, RILS (reacquire, identify and localise swimmers), is very much a product of the era, being developed to defend against hostile swimmers intent on attacking ships in port. As the US Navy in particular knows to its cost, protecting vulnerable assets, infrastructure and lives from such waterside asymmetric threats poses a major operational challenge, especially given the nature of the roles navies are increasingly being tasked with in the modern world. To counter a possible incursion, the RILS will travel to the suspect's location, deploy a gateway buoy and then activate its on-board imaging sonar. "This allows a remote operator to conduct the mission in real time," Frost explains, "RILS trails a threat that swims out of detection system range and sends GPS updates until help arrives. RILS will help to protect submarine bases, commercial ports and navy ships in foreign ports."
"For modern navies, the projection of force function is now intimately bound up with demands for cost-effectiveness."
Strategic inflexion techniques
For modern navies, the projection of force function is now intimately bound up with demands for cost-effectiveness, unprecedented target specificity and, increasingly, the reduction of risk. This is a strategic inflexion point which itself makes a compelling case for the adoption and development of UUV technologies. Not only can humans be replaced on potentially dangerous missions, but the current generations of vehicles point the way to how the tasks that later versions will undertake can be augmented. It is exactly the "look into the future" that Lieutenant Commander Kev Giles, fleet mine warfare capability manager, spoke of when the Royal Navy's new mine hunter AUV officially entered service, earlier in the year.
Defence analyst Mark Webster believes that those words may turn out to be prophetic ones, pointing to the off-the-shelf aspect of the mine countermeasures reconnaissance unmanned underwater vehicle – known as Recce. "It's a triumph of low-risk procurement and I'm sure we're going to see more like it over the coming years," he says.
Although Recce was what the MoD describe as "finely tuned to the Royal Navy's requirements" it was manufactured by the US firm Hydroid and based on their existing REMUS 600 AUV, with support from the US Office of Naval Research. The end result is undeniably impressive – able to dive to 200m and seek out mines autonomously for more than 20 hours, bristling with an impressive array of sensors including side scan, multibeam imaging and sub-bottom profiling sonar and reporting via GPS, RF and Wi-Fi. It will unquestionably change the face of UK mine countermeasures, but Webster suggests that the approach to its procurement might prove to be even more revealing as defence reviews and spending cuts bite. "When you're hearing navy spokesmen talking about 'low technological risk' and 'de-risking programmes' – like we did at the launch – then you really do have to take note."
The future battle space
The technology could also herald in a step change of an altogether different kind if the vision of future operations in the US Navy's UUV master plan ultimately becomes a reality, with roles extending far beyond mine-hunting and protection duties. "The role of the UUV as a force multiplier is about to get much more widely appreciated."
It calls for vehicles which can "sense, track, identify, target and destroy an enemy – all autonomously – and tie in with the full net-centric battle-space. UUV systems will provide a key undersea component for FORCEnet, contributing to an integrated picture of the battle space."
Engaging UUVs in the likes of intelligence, surveillance and reconnaissance missions, inspection and identification, payload delivery and time-critical strikes simply continues the trend established by other unmanned vehicles in the air and on the ground.
Theirs is a value proven in the crucible of war, but while Predator aerial strikes in Afghanistan are public knowledge, fewer are aware of the work done by their counterparts in the waterways of Iraq. With area denial widely expected to become more likely – and more extensive – as the prevalence of asymmetric conflict grows, the pressure will inexorably grow on a traditional naval doctrine that predicates access to the littorals for the projection of power onshore. That will inevitably influence the naval structure and, in the long run, that can only mean one thing; the role of the UUV as a force multiplier is about to get much more widely appreciated.