They Called It a 'Mine' to Hide Its Secret — It Sank 37 U Boats Without Missing
May 12, 1943. North Atlantic. An RAF Liberator spots a German U-boat on the surface. The submarine crash-dives. But instead of dropping blind depth charges, the pilot releases something new. A short, fat torpedo that can hear. It's called FIDO. Built from telephone switchboard parts, powered by a washing machine motor, and so secret that no wartime photographs exist. This is the story of the world's first acoustic homing torpedo — the weapon that followed the sound of a submarine's propellers through the dark water until it struck. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 📌 IN THIS VIDEO: • FIDO (Mark 24 Mine) — the first acoustic homing torpedo in history • Built in 10 months by Bell Labs, Harvard, and General Electric • Powered by a 7.5 hp motor and vacuum tube guidance system • 204 launched, 37 submarines sunk, 18 damaged • Kill rate: 18% vs 9.5% for depth charges — nearly twice as effective • The sinking of Japanese submarine I-52 and its cargo of gold • Sonobuoy recordings from the I-52 attack still survive in the National Archives • Why Germany never developed a countermeasure — they never knew it existed ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 📊 KEY FACTS: • December 1941 — Development begins at Harvard and Bell Labs • December 7, 1942 — First prototype test (Pearl Harbor anniversary) • March 1943 — First production units delivered • May 12, 1943 — First U-boat kill (U-456, RAF 86 Squadron) • $1,800 per unit — cheaper than a failed depth charge attack • 10,000 ordered → reduced to 4,000 (too effective to need more) • 37 submarines sunk = 15% of all U-boats destroyed by aircraft • Remained TOP SECRET throughout the war — no wartime photos exist ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 📚 SOURCES: • US Navy OEG Study No. 289 (August 1946) — Mark 24 effectiveness data • "Summary Technical Report of Division 6, NDRC, Vol 22" — Acoustic Torpedoes (1946) • Naval Submarine League Archive — "FIDO: The First U.S. Homing Torpedo" • US Naval Institute — "A Sub-Hunting Bloodhound" (Naval History Magazine, October 2017) • National Archives — Declassified Mark 24 Mine records • Jolie, E.W. — "A Brief History of US Navy Torpedo Development" (NUSC, 1978) • WW2 Database — Mark XXIV Torpedo operational history ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠️ DISCLAIMER: This documentary uses AI-generated narration and imagery for educational visualization of historical events. All facts presented are based on documented historical sources, archives, and academic research. Some scenes are artistic recreations intended to illustrate historical narratives. This content is created for educational purposes to preserve and share the history of World War 2. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🔔 Subscribe for more hidden stories of World War 2! ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ #WW2 #FIDO #Torpedo #UBoat #BattleOfTheAtlantic #SecretWeapon #SmartWeapon #AcousticTorpedo #SubmarineWarfare #History #HiddenHistory #Documentary #MilitaryHistory #BellLabs #Harvard #WWII ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ © All archival photographs are in the public domain or used under fair use for educational purposes. This video is intended for historical education.
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