The Deadliest Subs Ever Built (Only Killed Their Own Crews)

“The plans and schemes of tyrants are broken by many things. They shatter against cliffs of heroic struggle. They rupture on reefs of open resistance.” —Eric Flint, In The Heart of Darkness

In A Nutshell

Faced with the threat of German U-boats preying on Allied shipping early in World War I, the British navy unveiled the K-class submarine in an effort to match the Germans. Unfortunately, the K-ships were probably the most poorly designed vessels in naval history. Their entire service was marred by unmitigated disaster and death to the very men who sailed them, without even the consolation of proving their worth in actual battle.

The Whole Bushel

Rumors that the Germans were building submarines capable of speeds up to 22 knots on the surface prompted the Admiralty under First Sea Lord Jacky Fisher to devise a high-speed British counterpart. A tactical concept was also put forward to use such submarines as a screen plowing ahead of the main battle fleet that would engage the enemy ships before they could come within range of the British force. But technology at the time could only propose steam power as the means to achieve and maintain the required 24 knots cruising speed. The oil-fired steam turbine plant was heavy and took up a lot of space; the final dimensions of the K-submarine reflected this. The unwieldy ship was 103 meters (340 ft) long with a displacement of 1,980 tons (2,566 tons submerged)—too large for a submarine. The slightest error could send it diving out of control. Many K-subs hit the bottom of the sea bow first while the stern was still on the surface.

Above the boilers were two funnel uptakes and four 1-meter-diameter (37 in) air intakes. The funnels themselves were each protruding 1.5 meters (5 ft) high aft of the conning tower. This ridiculous design simply had too many holes—literally—for a submarine. Worse, the biggest holes were situated in a place that should be unmanned when submerging. In order to dive, the crew had to shut down the boilers, retract the funnels, and close all the hatches, valves, hull penetrations, intakes, and uptakes. It took four to five minutes for a K-sub to submerge. This means that a K-sub could not accomplish the standard crash dive to defend itself if attacked on the surface. Accelerating the dive only invited accidents like flooding and boiler room fires. The residual heat from the boilers was intolerable and the humidity hellishly oppressive once the ship was underwater. Despite all this, the Admiralty considered the steam monsters self-contained environments, and required the crews to live aboard full-time, even when in port. This, coupled with their subsequent reputation as sailing coffins, made the K-subs even more unpopular, and morale among the sailors became a major problem.

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Doom was with the ships from the very beginning. K-3 plunged to the bottom after losing control in a test dive, endangering the life of the future King George VI who was aboard as an observer. K-13’s ventilators failed to close and the flooded sub sank with the loss of 31 lives. K-6 was unable to surface. K-14 sprang a leak while at anchor and nearly asphyxiated her crew with chlorine gas. K-4 collided with K-1 off the Danish coast. K-7 was the only one recorded to have ever engaged the enemy. She attacked the German U-95 on June 16, 1917. Of the five torpedoes she fired, only one hit the mark—and didn’t explode. The U-95 submerged and escaped.

But the lowest ebb in the career of the ill-fated ships must be the tragicomedy of errors that was the “Battle” of May Island. The sea around the Firth of Forth was calm and the night of January 31, 1918 was clear when the British flotilla that accompanied the K-subs passed by May Island in single file. Gathering speed, the fleet unexpectedly saw a group of minesweepers crossing their path. K-14 swerved to avoid a crash and jammed her helm. K-22 (the former K-13) plowed into her, nearly tearing her bow. Both subs floated helpless and immobile when four battleships trailing behind loomed in the night. Three managed to avoid the disabled subs, but the Inflexible tore down K-22’s side. The light cruiser Fearless, trying to render assistance, rammed K-17, which sank in eight minutes. K-6 collided with K-4, almost severing her into two. K-7 then ran her over, and K-4 sank quickly after the double-whammy. The battleships bringing up the rear of the column barely swiped K-3, but the destroyers with them mowed down many K-17 survivors in the water, killing them. The light of dawn revealed the appalling losses: K-4 and K-17 sunk, and K-14, K-22, and Fearless badly damaged. Over 100 men were dead. No shots were fired.

Even after such a fiasco, the Admiralty refused to give up on the K-subs. After the war, K-5 disappeared off Scilly Islands with everyone on board. She was never found. K-15 sank at her pier in Portsmouth. It was only in 1931 that the last of the accursed subs, the K-26, was finally scrapped. They should have listened to Admiral Fisher who, back in 1913 when the idea was first brought up, expressed his doubts about the whole enterprise: “The most fatal error imaginable would be to put steam engines in submarines.”

Show Me The Proof

Photo credit: Oscar Parkes/Imperial War Museums/United Kingdom Government
“K” For Katastrophe: K Class Submarines In The Royal Navy
Steam Submarines: The Navy’s Dive to Disaster
Building the K Class Submarine, Jim Baumann