Rolls-Royce has revealed plans for an autonomous, single role naval vessel. Capable of operating beyond the horizon for more than 100 days, with a range of 3,500 nautical miles, the 60-metre vessel will displace 700 tonnes and reach speeds above 25 knots.
Rolls-Royce believes it could be used for coastal patrol and surveillance, logistics support, or as part of a fleet deployment, protecting conventional manned warships
“Rolls-Royce is seeing interest from major navies in autonomous, rather than remote-controlled, ships,” said Benjamin Thorp, Rolls-Royce, General Manager Naval Electrics, Automation and Control. “Such ships offer navies a way to deliver increased operational capability, reduce the risk to crew and cut both operating and build costs.”
With ever-increasing pressure on defence budgets, navies see unmanned technology as a route to reducing the through-life costs associated with crew. The removal of manpower from ships radically changes the ship design. Many of the habitation systems and accommodation compartments are removed, bringing immediate cost savings and making the vessel smaller.
The absence of crew increases the need for very reliable power and propulsion systems. Rolls-Royce’s approach is to blend advanced intelligent asset management and system redundancy in a cost-effective manner that avoids sacrificing the cost and volume savings achieved by removing the crew. A suite of autonomous support tools, developed by Rolls-Royce, such as energy management, equipment health monitoring and predictive and remote maintenance, will ensure the availability of unmanned vessels.
“The operational profile of these platforms will be more complicated than commercial unmanned vessels,” said Thorp. “They will be expected to sail from A to B on patrol, avoiding ships and other navigational hazards. At some point between A and B, they will detect something, maybe a submarine, and the mission will change to tracking and surveillance. The power and propulsion system will then need to adopt an ultra-quiet mode to avoid detection.”
These added complexities differentiate naval autonomy from commercial and highlight the challenges. Many of the technologies needed to make autonomous ships a reality already exist. Rolls-Royce has created what it believes to be the world’s first “intelligent awareness system”, combining multiple sensors with artificial intelligence, to help commercial vessels operate more safely and efficiently. Significant analysis of potential cyber risks is also being undertaken to ensure end-to-end security.
Building the future
In terms of development, Thorp explained that Rolls-Royce is looking to build on its reputation for robust and reliable naval propulsion systems to produce the open architecture autonomous solution required for the power and propulsion system.
he company will then seek partners to interface this with the naval navigation mission autonomous control systems. Over the next 10 years or so, the introduction of medium-sized unmanned platforms, particularly in leading navies, is expected and the concept of mixed manned and unmanned fleets will develop.
The autonomous platforms are likely to cover a range of single role missions, such as patrol and surveillance, mine detection or fleet screening, while the larger manned ships will cover the multi-role missions. By mixing the fleet composition in this way, Rolls-Royce believes navies will reap the operational and cost benefits offered by autonomous technology.
To be able to cover a number of single roles, Rolls-Royce is investigating the concepts of adaptability and modularity of the autonomous propulsion system to create a multi-mission platform. The vessel can then be used as a launch pad for unmanned aerial vehicles (UAVs) in one mission and then re-roled as a submarine detection platform in the next.
At the heart of the vessel is a robust and reliable power dense propulsion system. The initial design features a full electric propulsion system that requires fewer auxiliary systems (lubrication, cooling system etc) and offers better reliability levels than mechanical counterparts. It features two MTU 4000 Series gensets providing around 4MW electrical power to a 1.5MW propulsion drive.
The diesel engines could be replaced with small gas turbines, further improving the system’s reliability and reducing onboard maintenance. Permanent Magnet Azipull thrusters together with a bow-mounted tunnel thruster will make the vessel highly manoeuvrable.
To reduce fuel consumption and extend operational range, an additional 3,000kWh of energy storage will facilitate efficient low-speed loiter operations and the vessel will also be fitted with photovoltaic solar panels to generate power when the vessel is on standby. It should also be noted that autonomy doesn’t necessarily mean removing all of the crew from the vessels completely. Autonomous technology presents an opportunity to automate certain parts of the ship’s operations, but not everything.
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