10 American inventions that helped win D-Day

Business Insider

06-06-2025

M4 Sherman
The M4 Sherman was the backbone of the Allied armored force during World War II. Weighing roughly 40 tons, it was fast, reliable, and built by the thousands.
Sherman tanks proved key in helping the Allies break through German defenses at Utah and Omaha Beaches. Some were equipped with a bulldozer blade on the front that could cut through the defenses on the beach — and that would later function as hedgecutters used to break through wall-like hedges throughout Normandy.
Other Shermans were converted into Duplex Drive (DD) tanks — an amphibious design pioneered by the British. Outfitted with canvas flotation skirts and rear-mounted propellers, the DDs were meant to hit the beach alongside the first wave of infantry. While rough seas and weather doomed many off Omaha, those that made it ashore at Utah and Gold Beaches delivered crucial early support.
"Everybody thinks the Germans had the coolest tanks, and I categorically reject that," says Cartola. "The Shermans are relatively easy to maintain. The crews can fix them. They're relatively reliable with simple parts, and you're basically overwhelming the Germans with armor."
Invented by: Developed by the U.S. Army Ordnance Department in 1941 and mass-produced by automakers including Chrysler, Ford, and General Motors. The US manufactured 50,000 throughout the war.
Modern connection: While the Sherman was retired from combat decades ago, its simple, rugged design shaped post-war tank development and reinforced the importance of armored vehicles. Cartola considers the M1 Abrams tank that the US Army uses today the "grandson" of the Sherman.
'Walkie Talkie'
Nicknamed the "Walkie-Talkie," the Signal Corps Radio 300 was the first backpack radio for mobile infantry communication — and one of many radio varieties used on D-Day. Initially issued to US infantry in 1943, a soldier carried the nearly 40-pound SCR-300 transmitter and receiver on their back. With a three-mile range and 41 channels, the SCR-300 came in handy for real-time battalion-level communication during the highly chaotic, noisy beach landings
Invented by: Engineer Daniel E. Noble and his project team at Galvin Manufacturing Corporation. Originally founded by brothers Paul and Joseph Galvin pre-war to develop early car radios, Galvin became Motorola in 1947. Galvin engineers also developed a handheld, single-channel AM radio — the SCR-536, or "Handie-Talkie" — for battlefield communication at the platoon or company level.
Higgins boats
The Landing Craft, Vehicle, Personnel was a 36-foot landing craft made famous in the opening scene of the 1998 film, "Saving Private Ryan." Known as Higgins boats for its American inventor, 1,000 LCVPs were used to deliver troops across all five beaches during the Normandy landings, which marked the single largest deployment of LCVPs. Without these shallow-bottomed boats, landing directly on the open beaches with armor and troops would've been logistically impossible.
Invented by: New-Orleans-based shipbuilder and entrepreneur Andrew Higgins of Higgins Industries. He is said to have borrowed the front ramp idea from Japanese boats after seeing photos from the Sino-Japanese War. Gen. Dwight Eisenhower called Higgins "the man who won the war for us."
Landing ship, tank
The LST was a large cargo vessel used to land troops and armored vehicles without docking to a pier. Its large bow doors were designed to open to a ramp that let tanks and trucks drive directly from the ship to land. "To liberate continents, you need bulk. You need throughput…so you can do operations inland. And the LST allowed the Allies to do that without a fixed port," Cartola says.
Invented by: The LST was designed by American naval architect John C. Niedermair in response to Prime Minister Winston Churchill's request for a ship that would carry some 500 tons worth of tanks following the Dunkirk evacuation.
The DUKW amphibious truck
The DUKW (pronounced "duck") was a 6-wheel-drive amphibious truck capable of transporting about 5,000 pounds of cargo (or 24 troops) on land and water; a propeller could chug it through water with a max speed of 6 mph. "The beauty of this thing is, not only is it amphibious, but it can drive inland and provide supplies to troops well beyond the beach at up to 50 miles an hour," says Cartola.
Invented by: The DUKW was a product of collaborations among GMC, the naval architecture firm Sparkman & Stephens, and a Michigan-based bus manufacturer.
Modern connection: The DUKW pioneered a feature that allowed drivers to change the tire pressure from inside the cab to accommodate different terrains, which remains a common feature on military vehicles today.
Douglas C-47 transport
The C-47 Dakota, nicknamed "the workhorse," had many uses in both World War II theaters, from cargo and troop transportation to casualty evacuation and towing. More than 800 C-47s were used in the D-Day campaign to insert thousands of paratroopers and huge amounts of equipment behind enemy lines.
Invented by: Douglas Aircraft Company adapted its pre-war commercial airliner, the DC-3, for military use. It was relatively quiet and could carry up to 28 troops or 6,000 pounds of cargo. The US produced more than 10,000 C-47s.
A rebreather for divers
The Lambertsen Amphibious Respiratory Unit was a closed-circuit rebreather designed to recycle exhaled air by removing carbon dioxide and adding oxygen. The apparatus enabled divers to operate underwater for prolonged periods without leaving a trail of bubbles. Lambertsen, working for the Office of Strategic Services, trained OSS commandos to use the LARU for underwater reconnaissance and demolition missions in support of D-Day and other key landings.
Invented by: Christian Lambertsen, who, as a University of Pennsylvania medical student in the early 1940s, designed the LARU as a self-contained breathing device ideal for covert underwater missions.
Modern connection: Lambertsen himself coined the acronym "SCUBA" (Self-Contained Underwater Breathing Apparatus). His equipment and techniques paved the way for rebreathing technologies still used by military divers, including Navy SEALs. He's considered "the father of US Combat Diving."
Dummy paratroopers
These burlap, straw-stuffed mannequins were relatively small, lightweight decoys that could be dropped from planes to give the illusion of incoming paratroopers. A form of psychological warfare, the dolls were used to confuse and mislead the enemy. Dummies were sometimes equipped with noisemakers that sounded like gunfire or explosive charges that detonated on landing, adding to the illusion.
On the night of June 5, 1944, Allied planes dropped hundreds of these fake paratroopers, along with inflatable tanks, across the French countryside to give off the impression of airborne troops landing in areas far from the real drop zones. In several cases, German units responded to these fake drops.
Invented by: Inspired by the British "Rupert" paradummy, the American version, nicknamed "Oscar," was more compact, with the 3-foot-tall ones used on D-Day mainly manufactured in the UK.
Modern connection: While today's military decoys are generally more technologically advanced (e.g., electronic signature emitters), the principle of deception through false targets and diversionary tactics remains.
Proximity fuze
The proximity fuze — an electronic fuze for bombs, shells, or missiles that explodes when approaching a target — changed the rules of artillery in warfare; instead of needing a direct hit, anti-aircraft shells could suddenly detonate when they got close. They made Allied anti-aircraft fire far more effective in taking out German planes, helping protect the beachhead.
Invented by: Developed beginning in 1940 by American scientists at the Johns Hopkins University Applied Physics Laboratory, with critical contributions from British researchers. Key to the design was the miniature radio transmitter and receiver inside the shell that sensed nearby targets and triggered detonation.
Modern connection: The proximity fuze was a major step toward today's precision-guided weapons. Its combination of electronic sensing and remote detonation paved the way for modern guided bombs and missiles.
The Jeep
From the moment the first Allied troops hit the beaches of Normandy, this newly introduced American 4x4 was in motion, hauling supplies, ferrying wounded soldiers, towing anti-tank guns, and zipping across shell-scarred roads. Compact, reliable, and endlessly adaptable, it proved essential to the invasion of Normandy, along with many other battles.
Invented by: In 1940, facing the likelihood of entering the war, the US Army issued an emergency contract for a lightweight reconnaissance vehicle, prompting the development of the first Jeep prototype by Bantam Car Company in just 49 days. With Bantam lacking production capacity, Willys-Overland and Ford were tapped to manufacture the final design, cranking out hundreds of thousands of units over the course of the war. Some Jeeps were waterproofed for the landings, sealed tight and fitted with snorkels to wade ashore behind the infantry. Others were dropped by parachute into French fields with the 101st and 82nd Airborne, ready to drive the moment they hit the ground.
Modern connection: After the war, Willys began selling civilian versions, branding them as Civilian Jeep models and kickstarting America's obsession with off-road vehicles and SUVs.
Katie S. Sanders is a journalist based in New York City. Her reporting has brought her to prisons, the CIA, and the White House. Follow her at @KatieSSanders.