The 98-metre-long, adaptable offshore patrol vessel – the length of Big Ben – will act as a ‘mother ship’, operating remote and autonomous offboard systems for underwater surveillance and seabed warfare, vital to U.K. national security. The vessel will be formally handed over to control of the RFA in the next few days, several months ahead of schedule – following an acceleration of the acquisition announced by the Defence Secretary in November 2022. Shortly after arriving at Cammell Laird, the ship will be repainted and have critical military equipment installed, before taking up its role as the first of two Multi-Role Ocean Surveillance (MROS) ships, operated by the Royal Fleet Auxiliary (RFA) later this year. The vessel is due to enter operational service in Summer this year, with the programme for the acquisition of a second ship currently in concept phase.

Head of the Royal Fleet Auxiliary, Commodore David Eagles RFA, said:”This is an entirely new mission for the Royal Fleet Auxiliary – and one we relish. We have been entrusted with supporting a key operation to safeguard the UK’s infrastructure, security and prosperity and that fills all of us in the RFA with pride. These are really exciting times.”

Defence Secretary, Ben Wallace, said:”The first of two dedicated subsea surveillance ships will join the fleet this Summer, bolstering our capabilities and security against threats posed now and into the future. It is paramount at a time when we face Putin’s illegal invasion of Ukraine, that we prioritise capabilities that will protect our critical national infrastructure.”

The vessel – currently named ‘Topaz Tangaroa’, but due to be renamed as it joins the RFA fleet – was selected to meet the requirements of the Royal Navy, having been built four years ago to support a mix of underwater operations, including work on oil rigs, construction, maintenance and inspection work, as well as autonomous submarine operations. The 6,000-tonne vessel is equipped with a helipad, crane, and expansive working deck and features a ‘moon pool’ – a large access point in the underside of the hull through which submersible capabilities can be launched. The vessel, will be crewed by around two-dozen RFA sailors, while around 60 Royal Navy specialists will operate the undersea surveillance systems and other survey and warfare systems when embarked.

The first MROSS vessel, RFA Proteus, is a ready-built commercial vessel which has undergone conversion, whilst the second vessel will be purpose-built in the UK. As such, the two vessels are likely to have different designs and characteristics. Proteus was built in Norway in 2019 and will be equipped to operate autonomous submersibles. She has diesel-electric propulsion with powerful twin bow thrusters to “hold a precise stationary position when working over subsea installations”. She is also equipped with a moon pool, permitting a sheltered way for robot submersibles to be launched or recovered in high sea states. The ship is 98.1 metres-long with a flight deck, heavy duty crane and 1,000 square meters of cargo space. She has a displacement of 6,000 tonnes and will be crewed by around tow dozen RFA sailors and up to 60 Royal Navy specialists.