New drone submarine will protect Britain's underwater infrastructure after Nord Stream attacks

A new drone submarine will help defend Britain’s underwater infrastructure including internet cables and power lines from potential threats like the attacks that destroyed the Nord Stream gas pipelines.

The vessel, which is the size of a bus, will help the Royal Navy “dominate” underwater warfare and will be delivered within two years, Defence Secretary Ben Wallace has announced.

Speaking in Rome, where he was visiting his opposite number, Mr Wallace said: “In order to meet the growing threats to our underwater infrastructure, the Royal Navy needs to be ahead of the competition.”

He said the £15.4 million submarine “will help ensure we have the right equipment to protect the security of the UK and our Allies”.

Project Cetus – named after a mythological sea monster - is an experimentation platform to develop autonomous underwater systems. It will not carry weapons, but will monitor sub-sea activity to deter and detect attacks.

Designed to work side-by-side with crewed submarines, including Britain’s seven Astute-class hunter-killers, Cetus will be able to cover up to 1,000 miles in a single mission, which could last seven days.

At 12 metres long, 2.2 metres wide and weighing 17 tonnes, the drone will be the largest and most complex crewless submersible operated by a European navy.

The maximum depth Cetus can operate is classified but will exceed that of the submarines currently in service with the Royal Navy.

The vessel’s size means that it will fit inside a shipping container and can be quickly transported around the world to wherever it is needed.

First Sea Lord Admiral Sir Ben Key said: “This is a hugely exciting moment for Project Cetus as the Royal Navy surges ahead with the development of autonomous technology.

“This Extra Large Autonomous Underwater Vehicle is a capability step-change in our mission to dominate the underwater battlespace.”

Military chiefs have long been concerned about Britain’s vulnerability under the sea.

The attack on the NordStream pipeline in international waters between Sweden and Denmark in September, for which many defence experts blame Russia, was seen as a wake-up call to the vulnerability of critical national infrastructure.

Russia is known to have developed specialised crewed submarines capable of interfering with cables on the ocean floor.

Given the importance of internet cables and power lines under the sea, the MoD has made this a priority area for research and investment.

Earlier this year Ben Wallace ordered navy chiefs to review the balance between the surface and sub-surface fleets.

This year the MoD has also bought two surface ships designed to increase surveillance of the sea bed, with specially designed equipment to work at extreme depths.

The first of these, a new Multi-Role Ocean Survey Ship (MROSS) bought from Sweden, will be operational next year after refit. It is being rushed into service in the wake of Russia’s attack in Ukraine.

The Royal Navy will take delivery of MROSS in January 2023.

The Navy has also invested in a dedicated technology trials ship, the XV Patrick Blackett, to test new equipment. Cetus will be the equivalent for sub-sea experimentation.

Cetus is being designed and built for the Royal Navy by Plymouth-based tech firm MSubs.

Lieutenant Commander Andrew Witts from the Royal Navy’s Cetus team said: “One hundred and twenty years ago the Royal Navy had the foresight to invest in Holland 1 – the UK’s first submarine – which helped revolutionise naval warfare above and below the waves.

“Cetus is our first venture into large-scale, uncrewed submarines.

“It’s exciting, the possibilities are enormous, and I like to think Cetus could change the way we fight under the sea as much as those pioneers in Holland 1 did.”