"Flying Hoop" Explodes Mines by Magnetism
May 1943 Popular Mechanics

May 1943 Popular Mechanics

[Table of Contents] Wax nostalgic about and learn from the history of early mechanics and electronics. See articles from Popular Mechanics, published continuously since 1902. All copyrights hereby acknowledged.

Beginning in the early days of World War II (September 1, 1939 - September 2, 1945), Hitler's navy was laying mines in the water that were triggered by the magnetic field surrounding the metallic hulls of military and merchant ships. They usually floated just below the surface or even lay on the sea floor near shallow ports so as to avoid visual sighting, and then would detonate when ships passed overhead. It was like laying a spring leg trap on the ground and covering it with leaves. The ship's crew would never see it coming. The magnetic mines were as deadly and menacing as any U-Boat. The problem was so dire that by January 8, 1940, British engineers and flight crews had successfully designed and implemented a system for detonating the magnetic mines using a Vickers Wellington bomber (an amazing feat of aeronautical engineering in and of itself) fitted with a 51-foot diameter electromagnetic coil under its belly, powered by a Ford V-8 engine. The system was called Directional Wireless Installation (DWI). Because the war in Europe was still in progress, not much detail could be obtained or printed in 1943 when this news bit appeared in Popular Mechanics magazine. Now there are many good sources on the history of the Vickers Wellington DWI, including this great documentary video.

"Flying Hoop" Explodes Mines by Magnetism

When magnetic mines threatened the sea lanes around England late in 1939, the menace was met by equipping British bombers with a hoop device, holding a magnetic coil to which current is supplied by a Ford V-8 engine inside the hull. The magnetic field created within the ring is sufficient to explode the Nazi mines, which Hitler considered a prime "secret weapon." Existence of the ring-equipped bombers, long a secret, was revealed in the British Air Ministry's book, "Coastal Command."

Posted December 7, 2023