May 1942, somewhere in the North Atlantic, a supply ship called the SS Empire Caribou takes a torpedo amidships at 3:00 in the morning. The crew has less than 4 minutes before she goes under. 41 men drown in water so cold it stops the heart before the lungs fill. She is not special. She is Tuesday. By the spring of 1942, German U-boats are sinking Allied ships faster than the shipyards of Britain and America can build new ones.
In March alone, 273,000 tons of shipping vanishes beneath the Atlantic. In April, 430,000 tons. By June, the toll reaches 650,000 tons in a single month. Admirals on both sides of the Atlantic call it simply the crisis. The weapon supposed to stop them, the depth charge, has been in service since the First World War.
It is a steel drum packed with TNT dropped over the stern of an escort ship set to detonate at a preselected depth. It is blunt. It is imprecise. It has one devastating flaw. The moment an escort ship passes over a submerged submarine, sonar goes blind. The depth charges fall sometimes 10, sometimes 20 in a single pattern into churning deafened water.
And then everyone waits. By official Royal Navy statistics, out of 5,174 British depth charge attacks during the entire war, there are just 85 confirmed kills. A success rate of less than 2%. One kill for every 60 attempts. The submarines are winning. What no one in the Admiralty knows yet is that a scruffy, pockets overflowing royal engineer officer, a man whose superiors call him eccentric and whose weapon ideas are routinely called illegal, impossible, and absurd has just had an idea that will change the mathematics of submarine warfare
forever. His name is Millis Jefferis and in a secret workshop outside London, he is building something no naval officer has ever asked for. To understand why Millis Jefferis matters, you have to understand why the depth charge, the navy’s only real anti-submarine weapon, is a near perfect tool for failure. It works like this.
A destroyer or escort ship picks up a submarine on sonar, the asdic set that sends out a pulse and listens for the echo. Contact, the bearing is established. The ship turns to attack. But here is the problem that no admiral wants to say aloud. Sonar only scans ahead of the ship. As the vessel runs over the submarine’s position to drop its depth charges, the sonar cone swings away. Contact is lost.
For the final two or three hundred yards of the attack, run the most critical moment, the crew is firing blind. Completely, utterly blind. And it gets worse. When a depth charge detonates, the explosion creates a column of churning water, gas, and turbulence that scrambles sonar signals for up to 15 minutes afterward.
15 minutes in which a skilled U-boat commander can move his vessel hundreds of yards in any direction or dive deeper, or make a sharp turn, or simply sit still and wait. The attacking ship comes back, reacquires contact if it can, and has to start the whole process over. Again and again. Burning fuel. Using up depth charges. Giving the submarine time.
The statistics bear this out with brutal clarity. British convoy escorts throughout 1941 are conducting attack after attack with diminishing returns. In the first months of 1942, the kill rate with depth charges falls to less than one in 80 attacks. Navy strategists run the numbers and reach a conclusion they can barely speak.
At current rates of tonnage loss, Britain could be strangled into surrender by the end of 1942. The experts have proposals. Better trained crews. Tighter convoy patterns. More escorts per convoy. Improved sonar equipment. All of these are pursued. None of them fix the fundamental problem. The weapon that kills submarines requires you to lose contact with the submarine at the exact moment you fire it.
At the Admiralty and the Ministry of Supply, the solution being debated is incremental. Refinements, adjustments, the conventional wisdom among senior naval engineers is firm. A forward-throwing weapon, one that could project explosives ahead of the ship while sonar contact is maintained, is theoretically interesting, but practically impossible to build with acceptable accuracy at sea on a moving, pitching deck, in combat conditions.
Impossible is the word used in more than one official memorandum. In a country house outside Aylesbury in Buckinghamshire, a place called simply The Firs, a Royal Engineer Major who has been given extraordinary freedom by Winston Churchill himself is not particularly interested in what is impossible.
He is interested in what works. Major Millis Rawlin Jefferis is not by any standard Navy measure the right man to solve the Royal Navy’s submarine problem. He is Royal Engineers a sapper, a bridge builder and demolitions man. He has no formal naval training, no background in maritime weapons design. He has never served at sea. His expertise is in making things explode on land, sabotage devices, booby traps, the kind of irregular warfare contraptions that orthodox military men regard with deep suspicion.
He has been described by colleagues as a man who wanders the corridors of his workshop with his pockets perpetually stuffed with wires, batteries, and detonators, a walking safety hazard who generates ideas at a rate that alarms even his most tolerant superiors. His unit MD1, the Ministry of Defenses most unusual department, has been nicknamed Winston Churchill’s Toy Shop.
The name is affectionate. It is also slightly mocking. The established weapons community at the Ministry of Supply regards Jefferis and his team as clever amateurs producing gadgets that real soldiers don’t need. They have said so on paper repeatedly. What those critics do not fully appreciate is that Jefferis and his team have already produced the PIAT, the infantry anti-tank weapon that will go on to serve in every theater of the war.
They have produced limpet mines for sabotage operations. They have invented the sticky bomb. 26 different weapon systems will emerge from the Furs before the war ends. But in the autumn of 1941, Millis Jefferis turns his attention to the problem of submarines, not because anyone asks him to, but because the problem fascinates him.
The existing forward-firing weapon being tested, the Fairly Mortar, has just failed its sea trials. The principle, everyone agrees, is sound. The execution has collapsed. Jefferis picks up the failure report. He reads it carefully. He sets it down. And then, according to Major Stuart Macrae, his deputy, who will later write Winston Churchill’s Toy Shop, Jefferis says something that sounds almost bored.
The principle’s correct. The engineering is wrong. We can fix the engineering. The Fairly Mortar had tried to fire depth charges forward using a conventional barrel and shell configuration. Too heavy, too inaccurate. The recoil threatened to damage the ship’s deck. It was, in the language of engineers, overcomplicated.
Jefferis goes back to a simpler idea, the spigot mortar, a design that dates to the infantry trench warfare of the First World War. Instead of a barrel into which a shell is loaded, a spigot mortar works in reverse. A fixed steel spike, called a spigot, extends from the launcher. The projectile slips over the spike.
When the charge fires, the projectile is thrown forward cleanly without the weight or recoil of a conventional barrel. Jefferis and his team at the Furs design a launcher that holds not one spigot, but 24, arranged in a staggered array of six rows angled upward from the bow of the ship, each one holding a 65-lb projectile packed with 35 lbs of Torpex, a high explosive 50% more powerful by weight than TNT.
When fired, all 24 leave the launcher within a fraction of a second. They travel approximately 250 yards ahead of the ship. They fall in a circular pattern roughly 40 yards in diameter. And crucially, this is the insight that changes everything. They are fitted with contact fuses. They detonate only if they strike something solid.
This means if they miss, the sea is undisturbed. Sonar contact is maintained. The attack can be run again immediately. No 15-minute blackout. No turbulent water confusing the equipment. No blind guessing. They call it the Hedgehog because the empty launcher, its 24 steel spigots pointing skyward, looks exactly like the spines of the small, prickly English mammal.
When the weapon is demonstrated to senior Ministry of Supply officials for the first time in late 1941, the reaction is precisely what Jefferis has come to expect from men who have decided in advance that something cannot work. A senior naval ordnance officer watches the prototype fire a full salvo. He turns to his colleagues.
“You cannot put that on a warship,” he says flatly. “The recoil pattern alone will crack the deck plating. This is completely against naval safety regulations.” The room agrees. Jefferis is undeterred. He has a different audience in mind. The advantage of working in Winston Churchill’s toy shop, a unit that reports directly to the Prime Minister through his scientific adviser, Professor Frederick Lindemann, is that the chain of command runs very short indeed.
When the Ministry of Supply and the Admiralty’s Ordnance Establishment begin to formally block development of the Hedgehog, raising objections about deck stress, about the unconventional firing mechanism, about the legality of a weapon that had not gone through the established Bureau of Naval Ordnance approval process, Jefferis and his team do something orthodox officers cannot do.
They go to Lindemann, who goes to Churchill. In late 1941, a demonstration is arranged at which Churchill himself is present. The Hedgehog launches a full 24-bomb salvo into open water. The pattern is near perfect. Churchill watches in silence. The Ordnance Establishment representatives in attendance are appalled.
This has bypassed every standard process. It is, as one officer later complains in a memorandum, a weapon approved by political pressure rather than technical evaluation. Churchill reportedly turns to the room and says, “It works, doesn’t it?” The room erupts. Senior naval engineers argue that the weapon needs years of additional testing, that the contact fuse mechanism is insufficiently reliable, that proper protocols have been violated, that the forward-throwing concept, however appealing in theory, has not been
validated against live submarine contacts in combat conditions. Jefferis stands at the back of the room and says almost nothing. He doesn’t need to. Churchill has already decided. The Hedgehog enters service with the Royal Navy in January 1942. The United States Navy adopts it the same year, designating it the Mark 10 and Mark 11 anti-submarine projector.
What happens next confounds every prediction the critics have made. In the first months of deployment, results are mixed. The weapon’s potential is undermined by inadequate training. Crews who do not understand the contact fuse principle are frustrated when attacks produce no explosion. Many commanders, accustomed to depth charges that always detonate, interpret silence as equipment failure rather than a clean miss.
Then the Royal Navy sends instructors to the convoy escort bases. Trained crews start hitting submarines. The numbers begin to shift. By 1943, early statistics show one kill for every 5.7 Hedgehog attacks compared to one kill for every 60 depth charge attacks. And the best is still to come. In the United States Navy’s Pacific Fleet, the Hedgehog is installed aboard a new class of small escort vessels called destroyer escorts.
These are not glamorous ships. They are smaller than destroyers. They carry fewer guns. They are, in Navy slang, called small boys. One of these small boys is the USS England, hull number DE 635. She is commissioned on December 10th, 1943. She displaces 1,400 tons. Her crew numbers 186 men. She carries three 3-in guns, a battery of anti-aircraft weapons, depth charges, and one 24-barrel Hedgehog mounted at her bow.
Her executive officer is a 26-year-old lieutenant from Birmingham, Alabama, named John Williamson. Williamson is not a career naval officer. He is, by the assessment of the men who serve under him, something closer to a scientist with a uniform on. He is obsessive about data, about geometry, about the mathematics of convergence between a mortar salvo and a diving submarine.
While the England is still in San Francisco Harbor in early 1944, Williamson conducts unauthorized test firings of the Hedgehog into the bay. He is studying the spread pattern. He is building a mental model. He is getting ready. What John Williamson is about to do with the Hedgehog in the next 12 days will set a record that stands to this day, a record that no destroyer captain, no aircraft carrier, no submarine of any nation has ever broken.
If you want to see how one small ship’s executive officer destroys an entire Japanese submarine squadron, stay right here. And if you haven’t already, subscribe and hit the bell because the story of the USS England is the greatest naval hunting story ever told. May 13th, 1944, Fleet Radio Unit Pacific, the code-breaking operation that has been reading Japanese naval signals since Midway, intercepts a routine message.
A Japanese submarine, I-16, is transiting toward the Solomon Islands to deliver supplies to a garrison at Buin. The decoded signal contains the submarine’s route and schedule. The England, operating with two companion escort ships, USS George and USS Raby, is ordered to intercept. May 18th, 1944, the three ships depart Purvis Bay.
May 19th, 1944, 1:25 p.m. The England’s soundman, Roger Bernhardt, detects I-16 at a range of 4,300 yd. Lieutenant Williamson moves to the Hedgehog controls. The first attack is a miss. The second scores one contact detonation at 130 ft a hit, but not fatal. The I-16 goes deeper, twisting, trying to break contact. A third attack misses.
A fourth attack misses. I-16’s commander, the veteran Captain Masahiko Taniguchi, is skilled. He changes depth unexpectedly. He uses the thermal layers in the water column to confuse the sonar returns. But Williamson is running calculations. He is measuring the rate of depth change, the pattern of turns. 1:33 p.m.
Williamson calls his firing solution. 24 Hedgehog rounds leave the launcher in a single second. They arc through the Pacific afternoon. They strike the water ahead of the ship, already perfectly placed. Six contact detonations in rapid succession. Then, 2 minutes later, a catastrophic secondary explosion as I-16’s own torpedoes cook off.
The ship’s fantail rises 3 ft from the concussion. Men grab stanchions. A 3-x-6 mile oil slick rises to the surface. Over the next 24 hours, I-16 is gone. All hands lost. What Williamson and the England do not yet know is that this is only the beginning. American code breakers have intercepted a second Japanese signal.
Admiral Soemu Toyoda, commander of the Imperial Combined Fleet, has deployed seven submarines, Submarine Squadron 7, in a scouting line north of the Admiralty Islands. Their mission: to detect the direction of the next American offensive thrust and intercept any carrier task force. RO-104, RO-105, RO-106, RO-109, RO-116, RO-117.
Seven submarines. seven crews, a total of roughly 420 Japanese sailors forming an invisible barrier across 200 miles of Pacific Ocean. The England goes hunting May 22nd, RO-106 is detected, one Hedgehog salvo, destroyed May 23rd, RO-104, two attacks, destroyed May 26th, RO-116.
Williamson orders a deceptive sonar approach maintaining a steady ping rate to conceal the attack. At 0244 hours, he calls, “Fire.” Three to five contact detonations at 180 ft. RO-116 is gone. May 27th, RO-108, one salvo, six detonations at 250 ft, destroyed May 31st, RO-105, skippered by the experienced Captain Ryonosuke, leader of submarine division 51.
The Japan’s best submarine officers try for hours to prevent the England from getting a clean shot. Two American companion ships take their turns at the hunt and fail to sink her. Division Commander Haines finally signals the England, “Oh, hell, go ahead, England.” One salvo, six to 10 detonations. A massive explosion follows at 0741.
RO-105 is gone. In 12 days, the USS England, a ship 1/4 the displacement of a destroyer, crewed by 186 men, using a weapon the Naval Ordnance Establishment had called against regulations, has sunk six Japanese submarines. No ship in the history of naval warfare, before or since, has matched that record. In Tokyo, Admiral Toyota sends a signal to submarine squadron seven requesting their position for Operation A Go, the great carrier battle he is planning.
The response comes from Rear Admiral Owada. Squadron 7 has no submarines. Japanese submarine diaries recovered after the war document the fear that spread through the Pacific undersea fleet. In one account, a surviving Japanese submarine commander describes the effect of encountering a ship equipped with the Hedgehog. You hear nothing until impact.
There is no time to maneuver. The charges hit before you can respond. The traditional evasion tactics, depth changes, course reversals, thermal layer hiding, are all rendered useless by a weapon that does not need the ship to pass over you. The Hedgehog has made those submarines vanish in seconds. Six submarines, 12 days, one ship with a weapon the establishment called illegal.
In just a moment, we’re going to look at what happened to John Williamson after the war, why he refused every offer of fame, and why the weapon he used is still in service today. But first, if the story moved you, leave a comment below with the words, “Go ahead, England.” Let’s see how many of you are watching.
Now, back to the Pacific. After the war, the men who survived the convoy routes of the North Atlantic and the submarine war of the Pacific are asked to account for what had changed the battle. Again and again, the answer is the same. A veteran of the convoy escort service, speaking at a naval reunion in 1967, puts it simply, “Before the Hedgehog, we were guessing.
We were dropping depth charges into the ocean and hoping. After the Hedgehog, we were hunting. There’s a difference, and because of that difference, we came home.” By the end of the war, the Hedgehog is credited with the destruction of approximately 50 enemy submarines U-boats in the Atlantic and Japanese boats in the Pacific across 268 confirmed attacks.
A kill ratio more than 10 times better than the depth charge it supplemented. In 1944 and 1945 alone, 11 of the last 16 U-boats sunk by American escort vessels fall to the Hedgehog. Millis Jefferis, the Royal Engineer who built the thing in a country house workshop with pockets full of wires and detonators, is knighted in 1945.
He accepts the honor quietly. He does not seek interviews. He does not like memoirs. He declines to appear at ceremonies honoring the weapon that bears no individual inventor’s name. He returns to engineering work, eventually serving in Pakistan, and dies in 1963 without ever having spoken publicly about his role in building the device.
When asked about the honor, he is said to have replied in characteristic fashion, “The weapon worked. That was the point.” The Hedgehog principle, the forward-throwing, contact-fused, pattern-delivery anti-submarine weapon does not retire with the Second World War. It evolves. The Squid follows it. Then the Limbo system.
Then the Erbe 6000 series used by the Soviet and Russian navies. Today, the MP 54 lightweight torpedo and the ASROC rocket-propelled depth charge that arms American surface combatants draw their conceptual lineage directly from the idea Jeffers put on paper in 1941. The idea was simple. Fire forward. Only detonate on contact.
Keep the sonar running. The bureaucracy said it was impossible. The ordinance establishment said it was illegal. The experts said it would never work. And a 26-year-old executive officer from Birmingham, Alabama, standing at the bow of a 1400-ton escort ship in the Pacific, running the numbers, watching the oil slick spread across 3 miles of calm blue water, proved them all wrong.
Six times. In 12 days. There’ll always be an England in the United States Navy. Admiral E.J. King, Chief of Naval Operations, 1944.
