Can the Royal Navy exploit the drone revolution?

The Royal Navy is cancelling plans to buy conventional frigates as it transitions to a “hybrid navy” centred on AI-controlled drones. This, the outcome of Keir Starmer’s defence investment plan, and part of a £15bn increase in funding, is being sold as a radical departure in British defence policy. But the Royal Navy has been here before. You can see a hybrid ship today: HMS Warrior is on display at Portsmouth Historic Dockyard and came from another era, the 1860s, that gave rise to its own hybrids. So: a steam engine, but with masts and sails just in case, and an armament that hovered between an old-fashioned gun deck and trainable turrets.

But these hybrids didn’t last for long – this most radical of designs lasted only ten years in service (1863-1873). The new proved its worth, the old was shown to be deadweight, and naval architecture moved quickly to translate these findings into those “Castles of Steel” that were the ultimate symbols of mobile national power: the Dreadnought ships built in the early decades of the 20th century. It was a defining transition in naval power, finally pushed through by Admiral “Jackie” Fisher in the early 1900s.

Today’s transition could be equally definitive. Can – or should – we be early-adopters and get ahead of more stolid navies? Or are we betting the maritime farm on unproven technology that might work in the “big lake” of the Black Sea but will remain inappropriate to extended patrols in the North Atlantic during a stormy winter?

The case for change is made by Ukraine, which has stunned everyone by forcing a supposedly fearsome fleet to scurry deep back into Russia, all without a conventional navy of its own. A combination of special forces thinking and planning, tech-bro know-how, good intelligence, and imaginative use of air power, has defeated the Black Sea Fleet of Sevastopol. Sea drones steered remotely via Elon Musk’s Starlink satellites have acted as long-range, very smart torpedoes. Airborne drones and missiles picked off capital ships at sea, as with the sinking of the Moskva in April 2022, and have continued to pick them off when they sought the supposed sanctuary of home ports. When the UK designed the Stormshadow cruise missile, “submarine” was not in its assumed target set. The Ukrainians have expanded their scope.

In reality, this too is not that new. Parallels can be found from the 17th-century fire-ships, which devastated fleets while they were still in port. Or Lancaster bombers dropping Barnes Wallis’s “Tallboy” bombs on supposedly impregnable U-Boat pens, or using the same weapons to capsize the Nazi flagship the Tirpitz in November 1944 .Though I would question the wisdom of that last mission as that leviathan of a battleship, stranded in Northern Norway, was going nowhere and posed no real threat by that point in the war.

Indeed, the fate of the Tirpitz reveals the reality of the large battleship by the Second World War. Pretty early on it was proven to have had its day, even though the maritime flank remained as vital as ever: in the North Atlantic as the lifeline from the American arsenal to Europe; in the Pacific as a floating power-base that pushed relentlessly from island to island until a bomber dropped the atomic bombs from one such recaptured island. But while naval warfare continued to be important, the nature of the fleet changed dramatically.

Relatively simple Flower Class corvettes were produced at remarkable speed to defeat the U-Boats and keep the Atlantic convoys flowing. Repurposed Liberator bombers closed down German submarines’ hiding place in the mid-Atlantic “Gap”. Neither would have had pride of place at any Spithead Review before 1939. And yet, what remained of our capital ships were vital in providing gunfire support on D-Day. At Leyte Gulf in the Pacific in 1944, the largest naval battle in history was fought by a hybrid fleet led by aircraft carriers – but which still found a place for more conventional warships.

The reality is that transitions are rarely totally clean, black to white, overnight swaps. The hybrid fleet of tomorrow will not look like today’s, but parts will be recognisable. My intuition is that nuclear submarines will last quite a while yet, though their lives are about to get much more difficult. Anti-submarine warfare, a game of hide and seek where probability is forever recalculated, will be transformed by AI chewing on massive amounts of data that would previously have been little but noise. Will this new method of warfare need conventional frigates, which are now very sophisticated platforms? Or will it need something simpler; the modern version of the Flower Class corvette, playing the role of mother hen to a brood of wave-gliding drones festooned with sensors?

I sense the latter. But drones will find it difficult to protect the fleet from incoming hypersonic missiles. Conventionally, that requires a sophisticated, powerful radar at sea, and that means a destroyer class with a tall mast and space for large air defence missiles. Could they be replaced by myriad networked sensors, from space to surface vessels via blimps and drones, with the missiles on an “arsenal-barge” that are pointed and triggered remotely? In theory yes, but it is far from proven yet.

All the foregoing points to the need for extensive and deep experimentation. We now have compute power and digital twins where previously we had guesswork in peacetime and hard-earned lessons in war. Ukraine has offered us hard lessons at a very cheap price (not for them, for us). We should not discard those lessons because they are uncomfortable. But we should adapt them. The North Atlantic is not the Black Sea.

Nailing my colours here, I ought to suggest what the “HMS Warrior” of today might look like. My guess is that nuclear submarines are here to stay for a while; anti-submarine frigates will go hybrid quite quickly and will form motherships for arrays of sensors and drones. Destroyers will last for a while but might suffer a sudden decline as soon as off-board sensing and targeting removes the need for a large floating radar apparatus. And the aircraft carriers will live or die by the speed with which they can be adapted to carry long-range and long-endurance airborne drones to assist in all these missions, and all the others which are rapidly transitioning too.

Warfare is changing dramatically. In the past we have been innovative and bold: the longbow, the dreadnought and submarine, the tank and the aeroplane. Dare we cast aside the comfort blankets that have served us so well and be so bold again?