U.S. Navy uses RIMPAC international exercise to test new autonomous ships alongside traditional ships
The paradisiacal archipelago of Hawaii is the base of operations for the Rim of the Pacific (RIMPAC) military exercises, which are being held from the end of June to August 4 and form the largest naval training in the world. Of the 26 countries attending, the United States is the one that has sent the most material with ships like the USS Abraham Lincoln and others less known, but just as technologically advanced as they do not even need a crew.
In the little more than a month that RIMPAC will be active, a total of 38 ships, 4 submarines, more than 170 aircraft and some 25,000 troops will pass through, according to data provided by the U.S. Navy itself. Among them will be a small fleet of four unmanned surface vessels (USV) of the Unmanned Surface Vessel Division 1 based in the Californian port of San Diego.
Two of the autonomous ships sent to Hawaii are part of the so-called Ghost Fleet. In particular, they are the Ranger and Nomad vessels developed directly by the U.S. Pentagon within its Strategic Capabilities Office.
The Ghost Fleet Overlord program
The Ranger and Nomad are the first two in a saga of autonomous vessels that passed into the hands of the U.S. Navy in March of this very 2022.
The purpose of these first unmanned platforms – about which little is known – is to test autonomous navigation technology. One of the latest exploits published just over a year ago indicated that the Nomad had traveled 4,421 nautical miles (8,190 km) with 98% of the time in automatic navigation mode.
It is also known that the Navy is in the process of building two other autonomous vessels of the same family. The aim of these prototypes is that they become experimental platforms for the integration of new sensors for naval warfare and armament.
At the moment it is not very clear what specific equipment the vessels will carry, only the integration of SM-6 type anti-aircraft missiles in the Ranger has been reported. What does seem clear is that they are based on deeply modified fast transport boats of about 60 meters in length, with top speeds of around 40 knots (65 kilometers) per hour.
Sea Hunter and Sea Hawk from DARPA
As is the case with almost any U.S. military technology, DARPA is behind the development of another family of vessels, to which the Sea Hunter and Sea Hawk belong. This research agency under the Department of Defense has among its most advanced programs one that investigates the creation of unmanned craft specially designed for anti-submarine warfare.
The Sea Hunter, meanwhile, was commissioned in April 2016 after leaving Vigor Industrial’s shipyard in Portland, Oregon, to begin a period of autonomous navigation trials that concluded in 2018. It is a trimaran – a boat with 3 hulls – that inaugurated a family of vessels that was later – in 2021 – joined by the Sea Hawk, which is also participating in RIMPAC maneuvers.
The DARPA-powered system features an autonomous patrol function without human guidance and employs electro-optical sensors and on-board radar to avoid colliding with obstacles or other vessels. The Sea Hunter’s warfare equipment is kept secret and it is only known that between 2018 and 2019 it was planned to receive intelligence and submarine warfare systems, without further details.
Both vessels have a displacement mass ranging from 135 to 145 tons, depending on the cargo carried inside, in 40 meters in length. The propulsion system is represented by a pair of diesel engines with a 53,000-liter tank that gives them a range of about 19,000 kilometers. According to some reports, it is estimated that both Sea Hunter and Sea Hawk can maintain autonomous navigation for 30 to 90 days without having to call into port to refuel their tanks.
The relative success of this series of autonomous ships has led China, of course, to copy inch by inch the design for the construction of its own autonomous ship.