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History
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The Battle With No Enemy: Britain's Secret WWI Submarine Catastrophe
In the dark waters off the Scottish coast on a single night in 1918, the Royal Navy experienced a self-inflicted catastrophe known as the 'Battle of May Island.' In a fleet exercise, a series of collisions sank two submarines and killed over 100 sailors.
In the frigid, dark waters of the Firth of Forth, history holds one of the Royal Navy's most peculiar and tragic secrets. On the night of January 31, 1918, a formidable force of cruisers, destroyers, and two full flotillas of submarines set out on a major exercise codenamed EC1. By dawn, without a single enemy shot fired, two submarines lay at the bottom of the sea, four others were severely damaged, and over one hundred British sailors were dead. This was the 'Battle of May Island,' a catastrophe born not of combat, but of confusion, flawed technology, and the unforgiving fog of war.
A Weapon Born of Contradiction
At the heart of the disaster was the vessel itself: the K-class submarine. Conceived to solve a specific strategic problem—how to get submarines to keep pace with the fast-moving surface battle fleet—the K-class was a marvel of ambition and a litany of compromises. Unlike their diesel-electric counterparts, these were enormous, 339-foot-long boats powered by steam turbines for surface running. This gave them an incredible surface speed of 24 knots, faster than many destroyers. But this power came at a steep price. They were notoriously complex, with large funnels and air intakes that had to be sealed perfectly before diving. They were slow to submerge, handled poorly underwater, and were prone to accidental dives. Their crews, aware of their flaws, grimly nicknamed them the 'Kalamity Class'.
A Night of Errors
As the fleet steamed out of Rosyth in a single line stretching for miles, the conditions were ripe for disaster. It was a moonless night, and the ships were running with only a single, dimmed stern light for navigation to simulate wartime conditions. The plan was for the force to conduct exercises off the coast near the Isle of May. The first link in the tragic chain was forged when two minesweepers, not part of the exercise, were spotted ahead. To avoid them, the lead vessels made a sharp turn. In the darkness and confusion, the signal was slow to pass down the line.
The First Collision
Steaming at nearly 20 knots, the submarine K14's helm jammed, forcing it to veer out of line. It narrowly avoided one sister sub but was then struck by K22. The two submarines were locked together, crippled and dead in the water, directly in the path of the rest of the fleet thundering towards them. Crucially, strict radio silence meant they could not effectively warn the vessels behind them of the danger.
The Chain Reaction
What followed was a cascade of horrific collisions. The battlecruiser HMS Fearless, unable to see the disabled subs in time, ploughed directly into K17, slicing it open and sending it to the seabed in just eight minutes. Most of its crew were lost in the immediate aftermath. The following submarines, now aware of a catastrophe but blind to its specifics, began taking evasive action. In the chaos, K6, swerving to avoid the survivors of K17, struck K4. As K4 lay wounded, it was struck again by K7 and sank with all 56 hands. As one survivor later recalled, the scene was simply 'indescribable.' By the time the fleet could untangle itself, the full scale of the self-inflicted losses was devastating.
An Unspoken Tragedy
The Battle of May Island was an unprecedented disaster and a profound embarrassment for the Royal Navy. With the war still raging, news of such a staggering loss due to friendly error was unthinkable. The Admiralty immediately suppressed the story, placing the entire incident under the Official Secrets Act. The survivors were sworn to lifelong silence. Families were told their loved ones had been 'lost at sea,' a tragically vague explanation common in wartime. It wasn't until the 1990s that the full story was declassified, and the details of that terrible night finally came to light. The wrecks of HMS K4 and K17 now lie as protected war graves, a silent, submerged memorial to the more than 100 men who died in a battle that never was.